Heat exchanger, heat pump, dehumidifier, and dehumidifying method

ABSTRACT

A heat exchanger of a high heat exchange efficiency with a small size for its large heat exchanger duty is provided. The heat exchanger comprises: a first compartment  310  for flowing a first fluid A; a second compartment  320  for flowing a second fluid B; a first flow passage  251  passing through the compartment and for flowing the third fluid for exchanging heat with the first fluid A; and a second flow passage  252  passing through the compartment and for flowing the third fluid for exchanging heat with the first fluid B; the first and second flow passages  251, 252  are formed as an integral passage; the third fluid flows through from the first flow passage  251  to the second flow passage  252;  the third fluid evaporates in the first flow passage  251  at a specific pressure; the third fluid condenses in the second flow passage  252  at the approximately specific pressure. Since the third fluid flows from the first flow passage to the second flow passage, heat transfer from the first compartment to the second compartment is allowed. High heat transfer coefficient is achieved due to evaporating heat transfer or condensing heat transfer.

TECHNICAL FIELD

The invention relates to a heat exchanger, a heat pump, a dehumidifier,and dehumidifying method, in particular to a heat exchanger forexchanging heat between two fluids through a third fluid, a heat pumpand a dehumidifier provided with such a heat exchanger and to adehumidifying method by exchanging heat through the third fluid.

BACKGROUND ART

In order to exchange heat between large amounts of fluids of arelatively small mutual temperature difference, for instance between airconditioning process air and ambient air for cooling, a rotary type heatexchanger of a large capacity and a cross flow heat exchanger 3 as shownin FIG. 49 have been used. Such heat exchangers have been used forinstance in a desiccant air conditioning system to cool in advanceprocess air A to be introduced into a room using ambient air B beforesuch introduction occurs.

Such conventional heat exchangers have problems in that they are largein volume and take up too large an installation area, and that heatcannot be utilized sufficiently due to poor heat exchange efficiency.

Therefore, the object of the invention is to provide a heat exchanger ofa high heat exchange efficiency with a small size relative to its largeheat exchanging duty.

DISCLOSURE OF INVENTION

The heat exchanger of the invention comprises a first compartment forflowing a first fluid; a second compartment for flowing a second fluid;a first fluid passage passing through the first compartment for flowinga third fluid for exchanging heat with the first fluid; and a secondfluid passage passing through the second compartment for flowing thethird fluid for exchanging heat with the second fluid; and is configuredsuch that the first and second flow passages are formed as an integralflow passage, the third fluid flows through from the first flow passageto the second flow passage, the third fluid evaporates on the heattransfer surface located on the flow passage side of the first flowpassage at a specific pressure, and condenses on the heat transfersurface located on the flow passage side of the second flow passage atapproximately the specific pressure.

With such configuration described above, since the third fluid, or arefrigerant for example, flows from the first to the second fluidpassages it can transfer heat from the first to the second compartment.Since the third fluid evaporates at the specific pressure on the heattransfer surface located on the flow path side of the first flowpassage, the third fluid can take heat from the first fluid. Since thethird fluid 250 condenses at almost the specific pressure on the heattransfer surface located on the flow path side of the second flow path,the third fluid can give heat to the second fluid. Since theabove-mentioned heat transfer is evaporating heat transfer or condensingheat transfer, the heat transfer coefficient is much higher incomparison with only heat transfer by conduction or convection. Sincethe first and second flow passages are made as an integral body,arrangement as a whole is made compact. In the description above, theexpression of “at almost the specific condensing pressure” is usedbecause a flow is present from the first to the second flow passages,and there is a flow loss even though it is very small. Substantially,the pressure can be deemed to be the same.

With another configuration in which the second fluid contains moisture,the efficiency of cooling the third fluid by means of the second fluidcan be enhanced by utilizing the latent heat of evaporation of water.

With still another configuration in which a third fluid passage forflowing the third fluid for exchanging heat with the second fluid isadditionally arranged parallel to the second flow passage and passesthrough the second compartment, and in which the third fluidsubstantially bypasses the first compartment and is supplied to thethird flow passage and flows through the second compartment, it allowsthe third fluid to be of a phase different from the phase of the thirdfluid flowing through the first fluid passage to flow through the thirdflow passage.

It may also be configured such that the third fluid in liquid phase isintroduced to the first flow passage and the third fluid in vapor phaseis introduced to the third flow passage. For example, the fluid isseparated into vapor phase and liquid phase using a vapor-liquidseparator. In this way, it is possible to evaporate the liquid-phasethird fluid in the first flow passage, and condense the vapor-phasethird liquid in the third flow passage.

Another heat exchanger of the invention is configured such that aplurality of the first passages are disposed with different evaporatingpressures in the respective passages. With such a configuration,pressures in the plurality of flow passages are arranged in the high tolow or low to high order of the different pressures in the plurality offlow passages according to the temperature changes of the first fluidflowing through the first compartment or of the second fluid flowingthrough the second compartment. With such a configuration, the pluralityof flow passages in which evaporation or condensation occurs atdifferent pressures are arranged for example in the order of high to lowpressure. Therefore, for example, in case the first fluid is deprived ofsensible heat, temperature of the first fluid lowers during the time itenters and exits the first compartment. If the specific temperatures arearranged in the high to low order according to the temperature drop,heat exchange efficiency can be enhanced. This, in turn, enableseffective use of heat. In other words, a plurality of flow passages arearranged such that the first and second fluids flow in normal andreverse directions, respectively. In this way, the first and secondfluids flow in a counterflow manner to each other.

The heat pump of the invention comprises a pressure raiser for raisingthe pressure of a refrigerant; a first heat exchanger for condensing therefrigerant whose pressure has been boosted with the pressure raiser bytaking heat from the refrigerant with a high temperature fluid under afirst pressure; a first throttle for reducing to a second pressure therefrigerant that has been condensed with the first heat exchanger; asecond heat exchanger for evaporating the refrigerant that has beenreduced in pressure with the first throttle by the heat from the firstfluid under the second pressure, and for condensing the refrigerant,after the evaporation, by taking heat from the refrigerant with a secondfluid; a second throttle for reducing the pressure of the refrigerant toa third pressure, after being condensed with the second heat exchanger;and a third heat exchanger for evaporating the refrigerant that has beenreduced in pressure with the second throttle, by imparting heat from lowtemperature fluid under the third pressure. With such a configuration,since the second heat exchanger is provided for performing heat exchangeutilizing the evaporation and condensation of the refrigerant, heat canbe exchanged between the first and the second fluids with a high heatexchange efficiency. Incidentally, while the word “pressure raiser” inthe above description typically refers to the compressor for compressingthe refrigerant in vapor phase, it can also refer to a device comprisingfor example, an absorber that can be installed in an absorptionrefrigerator, a lean absorption pump for pumping up lean solution whichhas absorbed refrigerant in the absorber, and a generator for generatingthe refrigerant from lean solution pumped up with the pump.

A dehumidifier of the invention comprises a moisture adsorber containinga desiccant for adsorbing moisture in the process air; and a process aircooler for cooling the process air from which moisture has been adsorbedwith the desiccant. The process air cooler is configured to cool theprocess air by the evaporation of the refrigerant and to cool andcondense the evaporated refrigerant by means of a cooling fluid in theprocess air cooler.

The evaporated refrigerant is condensed typically by cooling with thecooling fluid on the downstream side as it flows in one direction as awhole in the process air cooler. The phrase “in one direction as awhole” refers to the fact that the vapor and also the liquid phaserefrigerant as a whole flow in the same direction, although there may belocal reverse eddies if the flow is turbulent.

A dehumidifying method of the invention comprises a first step ofcooling the process air with a refrigerant that evaporates at a lowpressure; a second step of raising to a high pressure the pressure ofthe refrigerant that has evaporated in the first step; a third step ofheating regeneration air for regenerating the desiccant with therefrigerant that condenses at the high pressure; a fourth step ofregenerating the desiccant by desorbing moisture from the desiccant withthe regeneration air heated in the third step; a fifth step of adsorbingmoisture in the process air with the desiccant regenerated in the fourthstep; a sixth step of cooling the process air from which moisture hasbeen removed by adsorption in the fifth step, by evaporating therefrigerant that has condensed in the third step at an intermediatepressure between the low and high pressures; and a seventh step ofcondensing the refrigerant that has evaporated at the intermediatepressure, at a pressure which is approximately the same as theintermediate pressure.

With the dehumidifying method described above, since the so-calledeconomizer cycle can be utilized, the refrigerating effect of therefrigerant can be enhanced and, in its turn, air can be dehumidifiedwith a high COP.

Another dehumidifier of the invention comprises a first refrigerant-airheat exchanger having a first refrigerant inlet-outlet and a secondrefrigerant inlet-outlet, and for causing heat exchange between therefrigerant and the process air; a compressor having an intake port anda discharge port for taking in and discharging the refrigerant, thesecond refrigerant inlet-outlet being disposed to be selectivelyconnectable to either the intake port or the discharge port; a secondrefrigerant-air heat exchanger having a third refrigerant inlet-outletand a fourth refrigerant inlet-outlet and for causing heat exchangebetween the refrigerant and the process air, with either the intake ordischarge port whichever has not been connected to the secondrefrigerant inlet-outlet, being disposed to be connectable to the thirdrefrigerant inlet-outlet; and a third refrigerant-air heat exchangerdisposed on the upstream side of the process air flow through the firstrefrigerant-air heat exchanger, having a fifth refrigerant inlet-outletand a sixth refrigerant inlet-outlet and for causing heat exchangebetween the process air, the refrigerant and the cooling fluid, with thefourth refrigerant inlet-outlet being disposed to be connectable toeither the fifth refrigerant inlet-outlet or the sixth refrigerantinlet-outlet; and a moisture adsorber disposed on the upstream side ofthe process air flow passing through the third refrigerant-air heatexchanger and having a desiccant for adsorbing moisture in the processair; and is configured such that whichever of the fifth refrigerantinlet-outlet or the sixth refrigerant inlet-outlet that has not beenconnected to the fourth refrigerant inlet-outlet is connected to thefirst refrigerant inlet-outlet; when the fourth refrigerant inlet-outletand the fifth refrigerant inlet-outlet are interconnected, the thirdrefrigerant-air heat exchanger cools the process air passing through thethird refrigerant-air heat exchanger by the evaporation of therefrigerant supplied from the fourth refrigerant inlet-outlet to thefifth refrigerant inlet-outlet, and cools and condenses the evaporatedrefrigerant with the cooling fluid, so that the condensed refrigerantcan be supplied to the first refrigerant-air heat exchanger.

In that case, since devices are arranged to permit selectiveconnections, the operation mode of the dehumidifier can be changed.

Still another dehumidifier of the invention comprises a moistureadsorber having a desiccant for adsorbing moisture in the process air;and a process air cooler, disposed on the downstream side of the processair flow relative to the moisture adsorber, for cooling the process airfrom which moisture has been adsorbed with the desiccant; and isconfigured such that the process air cooler cools the process air by theevaporation of the refrigerant and condenses the evaporated refrigerantin the process air cooler; and the process air cooler has a plurality ofevaporating pressures of the process air cooling refrigerant and,corresponding thereto, a plurality of condensing pressures at which therefrigerant is cooled and condensed with the cooling fluid. In thatcase, since there are a plurality of refrigerant evaporating pressuresand, corresponding thereto, a plurality of refrigerant condensingpressures, and since the plurality of evaporating pressures are set tobe different from each other, the plurality of evaporating pressures andcondensing pressures can be arranged in the high to low order or low tohigh. This makes it possible to perform the heat exchange between theprocess air and the cooling fluid in almost the so-called counter flowmanner.

Still another dehumidifier of the invention comprises a moistureadsorber having a desiccant which adsorbs moisture from the process airand which is regenerated with the regeneration air; a heat pump, havinga compressor for compressing a refrigerant, for pumping up heat from alow temperature heat source to a high temperature heat source using theprocess air as the low temperature heat source and the regeneration airas the high temperature heat source; and a process air cooler forcooling the process air from which moisture has been removed byadsorption with the desiccant; and is configured such that therefrigerant, before being drawn into the compressor, is heated with therefrigerant after being compressed with the compressor and after it hasexchanged heat with the regeneration air before regenerating thedesiccant. In that case, since the refrigerant before being drawn intothe compressor is heated with the refrigerant after being compressedwith the compressor and after exchanging heat with the regeneration airbefore it has regenerated the desiccant, that is, the refrigerant in analmost saturated state before being drawn into the compressor can beheated with the refrigerant which has exchanged heat, the dischargetemperature of the refrigerant compressed with the compressor increases,which in its turn permits the increase of the regeneration airtemperature.

Still another dehumidifier of the invention comprises a moistureadsorber having a desiccant for adsorbing moisture which in turn isdesorbed with regeneration air; a first heat pump for pumping up heatfrom a first evaporation temperature to a first condensation temperatureby circulating a refrigerant and configured to condense the refrigerant,after evaporating the refrigerant at a first intermediate temperaturebetween the first condensation temperature and the first evaporationtemperature, at a temperature which is almost equal to the firstintermediate temperature; and a second heat pump for pumping up heatfrom a second evaporation temperature which is lower than the firstevaporation temperature to a second condensation temperature which islower than the first condensation temperature by circulating arefrigerant and configured to condense the refrigerant, afterevaporating the refrigerant at a second intermediate temperature betweenthe second condensation temperature and the second evaporationtemperature, at a temperature which is almost equal to the secondintermediate temperature; and is configured such that the process airfrom which moisture is desorbed with the desiccant is cooled with therefrigerant that evaporates at the higher temperature of the first andthe second intermediate temperatures, subsequently is also cooled withthe refrigerant which evaporates at the lower intermediate temperature,then is cooled with the refrigerant which evaporates at the firstevaporation temperature, and then is cooled with the refrigerant whichevaporates at the second evaporation temperature; and the regenerationair is heated with the refrigerant that condenses at either atemperature which is almost equal to the first intermediate temperatureor a temperature which is almost equal to the second intermediatetemperature whichever lower, then is heated with the refrigerant thatcondenses at the rest of the two temperatures whichever higher, then isheated with the refrigerant that condenses at the second condensationtemperature, then is heated with the refrigerant that condenses at thefirst condensation temperature, and then the moisture in the desiccantis desorbed with the heated regeneration air.

With the configuration described above, since at least two heat pumpsare provided, heat drop through each heat pump is smaller in comparisonwith a configuration comprising only a single heat pump. Also, since theprocess air cooler is provided, each heat pump works in the economizercycle and makes it possible to provide a dehumidifier of a high COP.

Such a dehumidifier may also be configured such that the heat pump isprovided with a process air cooler and a condenser, with the condenserdisposed in a position vertically above the process air cooler. In thatcase, since the condensed refrigerant liquid flows downward, thegravitational force as well as refrigerant pressure can be utilized tofeed the refrigerant liquid from the condenser to the process aircooler. Therefore, it is suitable for use with the so-called lowpressure refrigerant.

A dehumidifier of the invention comprises a first air flow passagehaving a first intake port at its one end and a first discharge port atits other end so as to permit a first air flow from the first intakeport to the first discharge port; and a desiccant wheel through whichthe first air flow passes, and the rotary shaft of which is disposedvertically; and is configured such that one of the desiccant and thefirst air flow removes moisture from the other; and the first air flowpassage mainly includes a downward flow passage portion extendingvertically downward and an upward flow passage portion extendingvertically upward.

With such a configuration, since the dehumidifier is provided with thedesiccant wheel with its rotary shaft disposed vertically and with thepassage of the first air flow mainly including the downward flow passageportion extending vertically downward and the upward flow passageportion extending vertically upward, an orderly arrangement is possiblein which the first air flow through the dehumidifier mainly reciprocatesvertically, the first air flow need not change its direction immediatelybefore and after the desiccant wheel, and the humidifier is made compactwith a small installation compartment due to the vertically arrangedmajor devices.

In still another dehumidifier of the invention, the first intake port isdisposed on or in the vicinity of the top surface of the dehumidifierand the first discharge port is disposed on or in the vicinity of thetop surface of the dehumidifier. In that case, it is configured that thefirst air flow runs from the downward flow passage portion to the upwardflow passage portion.

Since the first intake port is disposed on or in the vicinity of the topsurface of the dehumidifier and the first discharge port is disposed onor in the vicinity of the top surface of the dehumidifier, the spacefrom the top surface or the vicinity of the top surface of thedehumidifier to a position of certain height in the dehumidifier can beutilized as the first air flow passage to simplify the first air flowpassage, and to reduce the size and installation area of thedehumidifier.

In still another dehumidifier of the invention, the first intake port isdisposed on or in the vicinity of the bottom surface of the dehumidifierand the first discharge port is disposed on or in the vicinity of thebottom surface of the dehumidifier. In that case, the first air flowruns from the upward flow passage portion to the downward flow passageportion.

Since the first intake port is disposed on or in the vicinity of thebottom surface of the dehumidifier and the first discharge port isdisposed on or in the vicinity of the bottom surface of thedehumidifier, the space from the bottom surface or the vicinity of thebottom surface of the dehumidifier to a position of certain height inthe dehumidifier can be utilized as the first air flow passage tosimplify the first air flow passage, and to reduce the installationarea.

Still another dehumidifier of the invention comprises a second air flowpassage having a second intake port at its one end and a seconddischarge port at its other end to permit a second air flow from thesecond intake port to the second discharge port; and is configured suchthat, in case moisture is removed from the desiccant with the first airflow, the moisture is removed from the desiccant to the second air flow,and that, in case moisture is removed from the desiccant to the firstair flow, moisture is removed from the desiccant with the second airflow; and that the second air flow mainly includes a flow passageportion vertically directed upward.

Since the second air flow passage is configured to mainly include thevertically directed upward flow passage portion, both the first and thesecond air flow passages are directed upward, and the first and thesecond air flow passages are arranged in good order, the first and thesecond air flow direction need not be changed immediately before andafter the desiccant wheel, major devices may be disposed in a verticaltier with one device over another, and the dehumidifier is made compactto reduce the installation area.

In still another dehumidifier of the invention, the second intake portis disposed on or in the vicinity of the bottom surface of thedehumidifier and the second discharge port is disposed on or in thevicinity of the top surface of the dehumidifier.

Since the second intake port is disposed on or in the vicinity of thebottom surface of the dehumidifier and the second discharge port isdisposed on or in the vicinity of the top surface of the dehumidifier, alength almost equal to the height from the bottom to the top surface ofthe dehumidifier can be utilized as a second air flow passage to makethe dehumidifier compact.

Still another dehumidifier of the invention is characterized in that thefirst air is process air.

Still another dehumidifier of the invention is characterized in that thefirst air is regeneration air.

Still another dehumidifier of the invention is characterized in that thefirst air is process air and the second air is regeneration air.

Still another dehumidifier of the invention comprises a first heatexchanger configured to cool the process air and that the desiccant isconfigured to remove moisture from the process air before the processair is cooled with the first heat exchanger.

Since the desiccant processes the process air before it is cooled withthe first heat exchanger, namely since the process air which has passedthrough the desiccant is cooled with the second heat exchanger, it ispossible to maintain a high heat exchange efficiency while making thedehumidifier compact and reducing the installation area.

Still another dehumidifier of the invention comprises a first heatexchanger configured to cool the process air; a second heat exchangerconfigured to heat the regeneration air; and a heat pump having a lowand a high temperature heat sources; and is configured such that thesecond heat exchanger constitutes the low temperature heat source whilethe first heat exchanger constitutes the high temperature heat source.

A dehumidifier of the invention comprises a process air blower (whichmay be a fan, depending on the air flow loss along the air path) forblowing process air; a regeneration air blower for blowing regenerationair; a compressor for compressing a refrigerant; a refrigerant condenserfor heating the regeneration air by condensing the compressedrefrigerant; a refrigerant evaporator for cooling the process air byevaporating the refrigerant condensed with the refrigerant condenser;and a desiccant wheel having a rotary shaft disposed vertically and adesiccant which is regenerated as the regeneration air heated with therefrigerant condenser passes through the desiccant and the process airis processed as it passes through the desiccant; and the process airblower, the regeneration air blower, and the compressor are located in aposition vertically below the desiccant wheel, while the refrigerantcondenser is located in a position vertically above the desiccant wheel.

With the configuration described above, in which the rotary shaft of thedesiccant wheel is disposed vertically, the process air blower, theregeneration air blower, and the compressor are located in a positionvertically below the desiccant wheel, and the refrigerant condenser islocated in a position vertically above the desiccant wheel, since themajor devices are arranged in the vertical direction, the devices arearranged in a compact size in the horizontal direction and theinstallation area is reduced. Here, the term “major devices” refers tothe blowers, the compressor, the desiccant wheel, the refrigerantcondenser, and the refrigerant evaporator and the like.

This application is based on the Japanese patent applications enumeratedbelow and the contents of these applications are incorporated herein byreference to constitute part of this application: Patent application10-199847 filed on Jun. 30, 1998, Patent application 10-207181 filed onJul. 7, 1998, Patent application 10-218574 filed on Jul. 16, 1998,Patent application 10-332861 filed on Nov. 24, 1998, Patent application10-333017 filed on Nov. 24, 1998, Patent application 10-345964 filed onDec. 4, 1998, Patent application 10-250424 filed on Aug. 20, 1998,Patent application 10-250425 filed on Aug. 20, 1998, Patent application10-274359 filed on Sep. 10, 1998, Patent application 10-286091 filed onSep. 22, 1998, Patent application 10-280530 filed on Sep. 16, 1998,Patent application 10-283505 filed on Sep. 18, 1998, and Patentapplication 10-299167 filed on Oct. 6, 1998.

The invention will be more perfectly understood from the followingdescription in details. Further scope of application of the inventionwill also become clear from the following description in details.However, the detailed description and specific examples are thepreferred embodiments of the invention and described only for thepurpose of illustration. Various changes and modifications may be madeby those skilled in the art within the spirit and scope of theinvention.

It is not intended to dedicate any disclosed embodiments to the public,and to the extent any disclosed modifications or alterations may notliterally fall within the scope of the claims, they are considered to bepart of the invention under the doctrine of equivalents.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic, cross sectional view of a heat exchanger as anembodiment of the invention.

FIG. 2 is a conceptual view of a heat exchanger as an embodiment of theinvention.

FIG. 3 is a conceptual view of a heat exchanger as an embodiment of theinvention.

FIG. 4 is a chart for explaining the heat exchange efficiency of heatexchange.

FIG. 5 is a flow chart of a heat pump and a dehumidifying airconditioner as embodiments of the invention.

FIG. 6 is a Mollier chart for the heat pump shown in FIG. 5.

FIG. 7 is a flow chart of a desiccant air conditioner using the heatpump as another embodiment of the invention.

FIG. 8 is a flow chart of a heat pump and a dehumidifying airconditioner as different embodiments of the invention.

FIG. 9 is a diagramatical, cross sectional view of a heat exchangersuitable for use in the heat pump shown in FIG. 8.

FIG. 10 is a Mollier chart for the heat pump shown in FIG. 8.

FIG. 11 is a flow chart of a dehumidifying air conditioner as anotherembodiment of the invention.

FIG. 12 are a sectional front and a sectional plan views, showing a heatexchanger suitable for use in the dehumidifying air conditioner shown inFIG. 11.

FIG. 13 is a Mollier chart for the heat pump shown in FIG. 11.

FIG. 14 is a moist air chart for explaining the operation of thedehumidifying air conditioner shown in FIG. 5.

FIG. 15 is a moist air chart for explaining the operation of thedehumidifying air conditioner shown in FIG. 8.

FIG. 16 is a perspective view of one configurational example of adesiccant wheel.

FIG. 17 is a table of operation modes of the dehumidifying airconditioner and operations of various devices as an embodiment of theinvention.

FIG. 18 is a flow chart of a heat pump and a dehumidifying airconditioner as an embodiment of the invention.

FIG. 19 is a flow chart when the dehumidifying air conditioner shown inFIG. 18 is operated in a heating operation mode.

FIG. 20 is a flow chart when the dehumidifying air conditioner shown inFIG. 18 is operated in a defrosting operation mode.

FIG. 21 is a table of operation modes of the dehumidifying airconditioner shown in FIG. 18 and operations of various devices.

FIG. 22 is a flow chart of a dehumidifying air conditioner as anotherembodiment of the invention.

FIG. 23 is a moist air chart for explaining the operation of thedehumidifying air conditioner shown in FIG. 22.

FIG. 24 is a Mollier chart for the heat pump used in the dehumidifyingair conditioner shown in FIG. 22.

FIG. 25 is a diagram for explaining enthalpy change amount versustemperature change of the regeneration air and the refrigerant used inthe dehumidifying air conditioner shown in FIG. 22.

FIG. 26 is a flow chart of a dehumidifying air conditioner as anotherembodiment of the invention.

FIG. 27 is a flow chart of a dehumidifying air conditioner as stillanother embodiment of the invention.

FIG. 28 is a flow chart of a dehumidifying air conditioner as stillanother embodiment of the invention.

FIG. 29 is a flow chart of a dehumidifying air conditioner as anembodiment of the invention.

FIG. 30 is a schematic cross sectional view of a heat exchanger suitablefor use as a process air cooler in the heat pump used in thedehumidifying air conditioner shown in FIG. 29.

FIG. 31 is a moist air chart for explaining the operation of thedehumidifying air conditioner shown in FIG. 29.

FIG. 32 is a Mollier chart for the heat pump used in the dehumidifyingair conditioner shown in FIG. 29.

FIG. 33 is an enlarged, schematic view of a process air cooler for usein the dehumidifying air conditioner as an embodiment of the invention.

FIG. 34 is a Mollier chart when the process air cooler of FIG. 33 isused for the heat pump used in the dehumidifying air conditioner shownin FIG. 29.

FIG. 35 is a schematic front cross sectional view, showing theconfiguration of a dehumidifying air conditioner as an embodiment of theinvention.

FIG. 36 is a flow chart of a dehumidifying air conditioner as anotherembodiment shown in FIG. 35.

FIG. 37 is a schematic, front cross sectional view showing theconfiguration of a dehumidifying air conditioner as another embodimentof the invention.

FIG. 38 is a schematic front cross sectional view showing theconfiguration of a dehumidifying air conditioner as another embodimentof the invention.

FIG. 39 is a schematic front cross sectional view showing theconfiguration of a dehumidifying air conditioner as another embodimentof the invention.

FIG. 40 shows the configuration of a dehumidifying air conditioner asanother embodiment of the invention, FIG. 40(a) shows a schematic frontcross sectional view, FIG. 40(b) shows the refrigerant flow through a4-way valve 265 in a heating mode, and FIG. 40(c) shows the refrigerantflow through a 4-way valve 280 in the heating mode.

FIG. 41 is a schematic front cross sectional view, showing theconfiguration of a dehumidifying air conditioner as another embodimentof the invention.

FIG. 42 is a schematic front cross sectional view, showing theconfiguration of a dehumidifying air conditioner as another embodimentof the invention.

FIG. 43 is a schematic front cross sectional view, showing theconfiguration of a dehumidifying air conditioner as another embodimentof the invention.

FIG. 44 is a schematic front cross sectional view, showing theconfiguration of a dehumidifying air conditioner as another embodimentof the invention.

FIG. 45 is a schematic front cross sectional view, showing theconfiguration of a dehumidifying air conditioner as another embodimentof the invention.

FIG. 46 is a schematic front cross sectional view, showing theconfiguration of a dehumidifying air conditioner as another embodimentof the invention, with the regeneration air blower omitted.

FIG. 47 is a schematic front cross sectional view, showing theconfiguration of a dehumidifying air conditioner as another embodimentof the invention.

FIG. 48 is a schematic side view, showing the configuration of thedehumidifying air conditioners shown in FIGs.46 and 47.

FIG. 49 is a perspective view of a conventional heat exchanger.

BEST MODE FOR CARRYING OUT THE INVENTION

While embodiments of the invention will be hereinafter described, thescope of the invention is not limited by the embodiments.

Now the embodiments of the invention will be described, referring to theappended drawings. Incidentally, counterparts in more than one of thedrawings are provided with the same or similar symbols and theexplanation of them may not be repeated.

FIG. 1 is a schematic cross sectional view of a heat exchanger as anembodiment of the invention. In the drawing, a heat exchanger 300comprises a first compartment 310 for flowing a first fluid or processair A and a second compartment 320 for flowing a second fluid orexternal (ambient) air B, disposed side by side with a partition wall301 interposed therebetween.

A plurality of heat exchanging tubes as fluid passages for flowing arefrigerant 250 are arranged generally horizontally to pass through thefirst compartment 310, the second compartment 320, and the partitionwall 301. Part of the heat exchanging tube passing through the firstcompartment is an evaporating section 251 as a first fluid passage (Aplurality of evaporating sections are referred to as 251A, 251B and251C. In case the plurality of evaporating sections need not bediscussed individually, hereinafter they will be simply referred to as251). Part of the heat exchanging tube passing through the secondcompartment is a condensing section second fluid passage (A plurality ofevaporating sections are referred to as 252A, 252B and 252C. In case theplurality of condensing sections need not be discussed individually,hereinafter they will be simply referred to as 252).

In the embodiment shown in FIG. 1, the evaporating section 251A and thecondensing section 252A are configured to an integral passage with asingle tube. The same is true for the evaporating sections 251B, 251Cand the condensing section 252B, 252C. Since the two sections 251 and252 are made up of a single tube and since the two compartments 310 and320 are disposed side by side with the partition wall 301 interposedbetween the two compartments, the heat exchanger 300 as a whole can bemade in a small size.

Such a configuration can be manufactured by arranging a plurality ofplate fins on the evaporating section side, one partition wall 301, anda plurality of plate fins on the condensing section side, each havingholes of a diameter nearly equal to (practically slightly greater than)the outside diameter of the heat exchanging tube, with the holesaligned, inserting a plurality of heat exchanging tubes into the holes,and expanding the diameter of the heat exchanging tubes by means of tubediameter expanding rods, hydraulic pressure, ball passage, etc. The formof the plate fin on the evaporating section side (first compartmentside) may be different from that on the condensing section side (secondcompartment side). For example, the plate fin on the evaporating sectionside may be provided with louvers or wrinkles to disturb the flow of thefirst fluid, while the plate fin on the condensing section side may beformed flat.

In the embodiment shown in FIG. 1, the evaporating sections are arrangedin the order of, from top downward in the drawing, 251A, 251B and 251C,and the condensing sections in the order of 252A, 252B and 252C from topdownward.

It is configured that the process air A as the first fluid enters fromabove the first compartment through a duct 109 and flows out downward,and that the external air B as the second fluid enters from under thesecond compartment through a duct 171 and flows out upward. That is tosay, the process air A and the external air B flow in counter directionseach other.

A water spray pipe 325 is disposed in the upper part of the secondcompartment 320, namely above the heat exchanging tubes which constitutethe condensing section 252. The water spray 325 is provided with nozzles327 at appropriate intervals so that water flowing through the waterspray pipe 325 is sprayed over the heat exchanging tubes whichconstitute the condensing section 252.

An evaporating humidifier 165 is disposed at the inlet for the secondfluid B the second compartment 320. The evaporating humidifier 165 ismade of a material having both moisture absorbing property andair-permeability such as ceramic paper or nonwoven fabric.

As shown in FIG. 2, the heat exchanger 300 may be provided with arefrigerant circulator 601 as a means for supplying and circulating aliquid state refrigerant. The refrigerant circulator 601 is, forexample, a pump for circulating a refrigerant liquid. In FIG. 2(a), therefrigerant liquid sent from the pump 601 is supplied to a header 235disposed at the inlet of the first fluid passage 251, then to theevaporating section 251 being the first flow passage connected to theheader 235, and evaporates there as it exchanges heat with the processair A flowing through the first compartment. The evaporated refrigerantflows to the condensing section 252 and there condenses by exchangingheat with the external air B flowing through the second compartment. Thecondensed and liquefied refrigerant reaches a header 245 connected tothe condensing section 252, flows down through a refrigerant pipeconnected to the header 245, flows down by gravity and stored in aliquid refrigerant tank 602 placed vertically below the header 245,returns to the inlet of the pump 601 through the refrigerant pipeconnected to the liquid refrigerant tank 602, and is supplied through adischarge pipe connected to the outlet of the pump 601 to the header235. Thereafter, the cycle consisting of the above steps is repeated.

The evaporating pressure in the evaporating section 251, in its turn thecondensing pressure in the condensing section 252, namely the specificpressure (the second pressure) of the invention is determined by thetemperature of the process air A and the temperature of the external airB. Since the heat exchanger 300 in the embodiment shown in FIGS. 1 and 2utilizes heat transfer by evaporation and heat transfer by condensation,it is excellent in both heat transfer coefficient and heat exchangeefficiency. Since the refrigerant as the third fluid flows through theevaporating section 251 to the condensing section 252, namely since itis forced to flow generally in one direction as a whole, it has a highheat exchange efficiency. The heat exchange coefficient Φ will bedescribed later, referring to FIG. 4.

The inside surfaces of the heat exchange tubes constituting theevaporating section 251 and the condensing section 252 are preferablymade to be high performance heat transfer surfaces by providing spiralgrooves like the inside surface of a rifle gun barrel. The refrigerantliquid flowing along the inside ordinarily flows so as to wet the insidesurface. If the spiral grooves are provided, heat transfer coefficientincreases as the boundary layer of the flow is disturbed.

While the process air A flows through the first compartment 310, thefins provided on the outer side of the heat exchange tubes arepreferably made in a louver shape to disturb the flow of the fluid.However, in case water is sprayed, the fins are preferably flat andcovered with an anti-corrosion coating. This is to prevent corrosivesubstances that may be present mixed in with the water from corrodingthe fins and the tubes as such substances become high in concentrationas water evaporates. Also, the fins are preferably made of aluminium,copper, or alloys thereof.

In the case of FIG. 2(b), a throttle such as an orifice is interposedbetween the header 235 and the evaporating section 251. With such aconfiguration, it is possible to provide a heat exchanger of anextremely high heat exchange efficiency because heat can be exchangedbetween the first and the second fluids in counterflow manner. Theplurality of evaporating sections 251A, 251B and 251C are respectivelyprovided with throttles 250A, 250B and 250C. The correspondingcondensing sections 252A, 252B and 252C are respectively provided,between the header 245 and them, with throttles 240A, 240B and 240C.

In such a configuration, the process air A flows at right angles to theheat exchange tubes so as to come into contact in succession with theevaporating sections 251A, 251B and 251C in that order in the firstcompartment to exchange heat with the refrigerant. The external air B ofa lower temperature at the inlet than the process air temperature isforced to flow at right angles to the heat exchange tubes so as to comeinto contact in succession with the condensing sections 252C, 252B and252A in that order. In such a case, while the evaporating pressures(temperatures) of the refrigerant are determined for each group ofsections provided with the throttles, in the evaporating section, theyare in the order of high to low for the sections 251A, 251B and 251C. Inthe condensing section, they are in the order of low to high for thesections 252C, 252B and 252A. Since the flows of the process air A andthe external air B are in counter flow with each other, an extremelyhigh heat exchange heat exchange efficiency Φ such as over 80% can berealized.

The specific pressures, or the evaporating pressures in the plurality ofevaporating sections 251A, 251B and 251C can be different from eachother as a result of providing mutually independent throttles 250A, 250Band 250C at the inlets of the respective evaporating sections. Theprocess air is made to flow into the first compartment so that it comesinto contact with evaporating sections 251A, 251B and 251C in thatorder. Since the process air is deprived of its sensible heat, itstemperature lowers along the length from the inlet to the outlet. As aresult, the evaporating pressures in the evaporating sections 251A,251B, and 251C lower in that order, and the evaporation temperatures arearranged in high to low order.

In exactly the same manner, the condensing temperatures are in the orderof 252C, 252B and 252A from low to high. Like the evaporating sections,since the condensing sections are provided with mutually independentthrottles 240A, 240B and 240C, they can have mutually independentcondensing pressures and temperatures. When the external air is made toflow from the inlet to the outlet of the second compartment so as tocome into contact with the condensing sections 252C, 252B and 252A inthe order, the condensing pressures are arranged in that order.Therefore, when the flows of the process air A and the external air Bare noted, since they are in the so-called counterflow, as describedabove, a high heat exchange efficiency can be achieved.

Since the refrigerant as a whole flows in one direction from theevaporating section 251 to the condensing section 252, the evaporatingpressure is slightly higher than the condensing pressure. However, sincethe evaporating section 251 and the condensing section 252 areconfigured with a continuous heat exchange tube, the evaporatingpressure is deemed to be substantially the same as the condensingpressure.

Another embodiment of the invention will be described in reference toFIG. 3. FIG. 3 shows an arrangement, based on the heat exchanger shownin FIG. 2, in which the first compartment is separated from the secondcompartment, and furthermore, the first fluid passage is separated fromthe second fluid passage. That is to say, the evaporating sections 251A,251B and 251C are respectively connected to the condensing sections252A, 252B and 252C. Headers are provided between the first and thesecond flow passages for each of the sections A, B and C and connectedthrough piping. Also in this arrangement, the performance of the heatexchanger remains basically the same, but ease of manufacture and layoutflexibility are improved.

Referring to FIG. 4, heat exchange efficiency will be described. In FIG.4, the symbol TP1 stands for the temperature of the fluid on the highertemperature side at the inlet of the heat exchanger, TP2 for the outlettemperature, TC1 for the fluid on the lower temperature side at theinlet of the heat exchanger, and TC2 for the outlet temperature. Whenthe symbol φ is assumed to be the heat exchange efficiency, and thecooling of the fluid on the higher temperature side is noted, namelywhen the purpose of the heat exchange is cooling, φ=(TP1−TP2)/(TP1−TC1).When the heating of the fluid on the lower temperature side is noted,namely name when the purpose of the heat exchange is heating,φ=(TC2−TC1)/(TP1−TC1).

With the heat exchanger of the invention described above, since thethird fluid flow through from the first fluid passage to the secondfluid passage, heat can be transferred from the first compartment to thesecond compartment. Since the third fluid evaporates at the specificpressure on the heat transfer surface on the fluid path side of thefirst fluid passage, the third fluid takes heat from the first fluid.Since the third fluid condenses at nearly the same pressure as thespecific pressure on the heat transfer surface on the fluid path side ofthe second fluid passage, the third fluid imparts heat to the secondfluid. Since the above-mentioned heat transfer is effected byevaporating or condensing heat transfer, the heat transfer efficiency ismuch higher in comparison with heat transfer by conduction orconvection. Therefore, when it is used, for example, in desiccant airconditioner, it can be favorably used in place of a cross flow type heatexchanger of a low heat exchange efficiency or a rotary type heatexchanger of a large volume, and it can remarkably improve theefficiency of the desiccant air conditioner.

As will be described later, referring to FIG. 12, when a vapor-liquidseparator is provided, heat exchange in the heat exchanger of theinvention is uniform since the refrigerant gas and the refrigerantliquid are separated.

Referring to FIG. 5, an embodiment of a heat pump HP1 of a high COP willbe described together with explanation of an embodiment of a desiccantair conditioner incorporating the heat pump HP1, having a high COP andarranged so as to be compact in size. The heat exchanger shown in FIG. 1is suitable for use in the heat pump HP1. FIG. 6 is a Mollier chart forexplaining the refrigerant cycle of the heat pump HP1 or the firstembodiment of the invention.

This air conditioning system is to lower the humidity of the process airby means of a desiccant (drying agent) and to maintain in a comfortableenvironment the air conditioning space to which the process air issupplied.

Referring to FIG. 5, the path of the process air as the first fluid willbe described. As shown, air to be processed RA is taken from a space 101to be processed using a blower 102 through an intake passage or a duct107. The discharge port of the blower 102 is connected through a duct108 to the inlet on the process air side of a desiccant wheel 103 whichserves as a moisture adsorber. The outlet on the process air side of thedesiccant wheel 103 is connected through a duct 109 to the inlet of afirst compartment 310 of a heat exchanger 300 serving as the second heatexchanger explained in reference to FIG. 1.

The process air is dried as its moisture is removed by adsorption in thedesiccant wheel 103 and reaches the heat exchanger 300 through the duct109. The temperature of the process air is raised by the heat ofadsorption as the moisture is adsorbed with the desiccant.

In the first compartment 310, the process air is cooled by therefrigerant that evaporates in the evaporating section 251. The processair outlet of the first compartment 310 is introduced through a duct 110to a cooler 210 which serves as a third heat exchanger. The process airwhich has been dried and cooled to an extent is further cooled here,made into the process air SA having an appropriate humidity and anappropriate temperature, and returned through a duct 111 to the airconditioning space 101.

Next, the path of the outside (ambient) air as the second fluid on thesecond compartment 320 side of the heat exchanger 300 will be described.A duct 171 for drawing outside air from the outdoors OA is connected tothe inlet of the second compartment 320. The outside air drawn inthrough the duct 171 is humidified with an evaporating humidifier 165,deprived of its sensible heat, and its temperature lowers. The outsideair of the lowered temperature, when it passes through the secondcompartment 320, takes heat from the refrigerant in the condensingsection 252, and causes the refrigerant to condense.

The heat exchanging tube 252 is arranged to receive spray water from aspray pipe 325. The outside air is cooled also with the sprayed water.The sensible heat of the outside air and the evaporating heat of thesprayed water cause the refrigerant in the condensing section 252 tocondense.

A duct 172 is connected to the outside air outlet of the secondcompartment 320. A blower 160 is disposed in the middle of the duct 172.The outside air that has been used for condensing the refrigerant isdischarged as exhaust EX through the duct 172 to the outdoors.

Next will be described the path of the refrigerant which serves as thethird fluid for the heat pump HP1. As shown, the refrigerant gascompressed by a refrigerant compressor 260, which serves as a pressureraiser, is introduced to a regeneration air heater (as a cooler orcondenser when seen from the refrigerant side) 220 through a refrigerantgas piping 201 connected to the discharge port of the compressor 260.The temperature of the refrigerant gas compressed with the compressor260 is raised by the heat of compression which, in turn, heats theregeneration air. The refrigerant gas itself condenses as it is deprivedof its heat.

The refrigerant outlet of the heater 220 is connected to the inlet ofthe evaporating section 251 of the heat exchanger 300 through arefrigerant passage 202. A throttle 230 (serving also as a header) isprovided in a position which is in the middle of the refrigerant passage202 and in the vicinity of the inlet of the evaporating section 251. Inthis embodiment, the header 230 is constituted to include the throttle.

The refrigerant liquid coming out of the heater 220 is reduced inpressure, expanded, and part of it evaporates (flashes). The refrigerantin the state of liquid-gas mixture reaches the evaporating section 251and here flows so as to wet the inside wall of the tubes of theevaporating section, evaporates, and cools the process air flowing inthe first compartment 310.

Since the evaporating section 251 and the condensing section 252constitute a continuous tube, or an integral flow passage, therefrigerant that has evaporated (and that which has not evaporated)flows into the condensing section 252 and is deprived of its heat by thesprayed water and by the outside air flowing through the secondcompartment. However, although not shown, it may alternatively beconfigured such that the first section 310 and the second section 320are separated, and accordingly the evaporating section 251 and thecondensing section 252 are made separate, and respectively installed indifferent places. In that case, the evaporating section 251 and thecondensing section 252 will be communicated with each other through, forexample, piping.

The outlet side of the condensing section 252 is connected to the cooler(as an evaporator when seen from the refrigerant side) 210 through arefrigerant liquid piping 203. A throttle 240 (serving also as a header)is provided in the middle of the refrigerant liquid piping 203. Whilethe attachment position of the throttle 240 may be anywhere between justafter the condensing section 252 and the inlet of the cooler 210,preferably it is just before the inlet of the cooler 210. The reason isthat the insulation of the piping becomes thicker, because therefrigerant after the throttle 240 becomes considerably colder than theatmosphere. In that case, the throttle 240 and the header are preferablyseparate. The refrigerant that has condensed in the condensing section252 is reduced in pressure by the throttle 240, expanded to lower thetemperature, evaporates as it enters the cooler 210, and cools theprocess air with its evaporation heat. The throttles 230, 240 may be forexample orifices, capillary tubes, expansion valves, or the like.

The refrigerant vaporized into the gaseous state in the cooler 210 isled to the intake side of the refrigerant compressor 260 and the abovecycle is repeated thereafter.

Next the path of the regeneration air B for regenerating the desiccantwill be described. The outside air drawn in from outdoors through anoutside air duct 124 is fed into a sensible heat exchanger 121. Thesensible heat exchanger 121 is a heat exchanger of a rotor-shape andconfigured such that a large volume rotor filled with a heat storagematerial rotates in a housing divided into two compartments, with onecompartment for flowing the outside air just drawn in while the othercompartment is for flowing a fluid for exchanging heat with the outsideair.

The outside air heated to a certain extent with the sensible heatexchanger 121 reaches the heater 220 through a duct 126, here furtherheated with the refrigerant gas to a higher temperature, and introducedas the regeneration air through a duct 127 into a regeneration side ofthe desiccant wheel 103.

The regeneration air after regenerating the desiccant with the desiccantwheel 103 is led to the sensible heat exchanger 121 through ducts 128,129 interconnecting the desiccant wheel 103 and the other compartment ofthe sensible heat exchanger 121. A blower 140 is provided between theducts 128, 129 to draw in outside air, and to flow the regeneration air.

The regeneration air after exchanging heat with (giving heat to) theoutside air is discharged as exhaust EX through a duct 130.Incidentally, the positions of the blowers 102, 140 and 160 are notlimited to those described above but may be any positions along therespective fluid passages for blowing.

In the described process air cooler 300 for use in the heat pump and thedehumidifying air conditioner, it is assumed that the refrigerant flowsthrough in one direction from the evaporating section 251 side to thecondensing section 252 side. However, another configuration may be usedin place of the above: for example, the evaporating section 251 and thecondensing section 252 are made in an integral tube with both its endsclosed, as a so-called heat pipe so that the refrigerant condensed inthe condensing section 252 is returned to the evaporating section 251 byutilizing capillary phenomenon or the like, and vaporized again there,thus causing the refrigerant to circulate within the single tube. Inthat case too, the heat transfer likewise utilizes both evaporation andcondensation and such advantages are obtained that a high heat transfercoefficient is achieved and that the constitution as the heat exchangerfor exchanging heat between the process air and the cooling fluid can besimplified.

Referring to FIG. 6, the function of the heat pump HP1 as an embodimentof the invention in the air conditioning system shown in FIG. 5 will bedescribed. FIG. 6 is a Mollier chart when HFC 134 a is used as therefrigerant. In this chart, the horizontal axis represents enthalpy andthe vertical axis represents pressure.

As shown, the point a corresponds to the state at the refrigerant outletof the cooler 210 shown in FIG. 5, in a saturated gas state. Thepressure is 4.2 kg/cm² as the third pressure, the temperature is 10° C.,and the enthalpy is 148.83 kcal/kg. This gas is drawn in and compressedwith the compressor 260 and the state of the gas at the discharge portof the compressor 260 is shown at the point b. In this state, thepressure is 19.3 kg/cm² as the first pressure, and the temperature is78° C., in the superheated state.

The refrigerant gas is cooled in the heater 220 and reaches the staterepresented by the point c on the Mollier chart. At this point, is therefrigerant in a saturated gas state with a pressure of 19.3 kg/cm² anda temperature of 65° C. Further cooling and condensation under thispressure leads to the state of point d. This point is in a saturatedliquid state with the same pressure and the temperature as those at thepoint c, namely 19.3 kg/cm² and 65° C., and with an enthalpy of 122.97kcal/kg.

The refrigerant liquid is reduced in pressure with the throttle 230 andflows into the evaporating section 251 of the heat exchanger 300. Thisstate is represented by the point e on the Mollier chart. Thetemperature is about 30° C. The pressure is the second pressure of theinvention or a specific pressure. In this embodiment, an intermediatevalue (intermediate pressure) between 4.2 kg/cm² and 19.3 kg/cm², namelya saturation pressure corresponding to 30° C. Here, the refrigerant isin the state of mixture of liquid. and gas as part of the liquid hasevaporated. The refrigerant liquid evaporates in the evaporating section251 under the second pressure and reaches under the same pressure as thestate represented by the point f which is between the saturated liquidline and the saturated gas line. Here, almost all the liquid hasevaporated. Incidentally at the point e, the ratio of refrigerant liquidto gas is the inverted ratio of the difference between the enthalpy atthe points where the saturated pressure line of 30° C. crosses thesaturated liquid line and the saturated gas line and the enthalpy at thepoint (d). Therefore, as is clear from the Mollier chart, liquid isgreater in weight. However, since the gas is overwhelmingly greater involumetric ratio, a large amount of gas mixes with the liquid in theevaporating section 251, the liquid evaporates in the state of wettingthe inside surfaces of the tubes of the evaporating section 251.

The refrigerant in vapor phase or in vapor-liquid mixture phaserepresented by the point f flows into the condensing section 252. In thecondensing section 252, the refrigerant is deprived of its heat by theoutside air flowing through the second compartment and/or with thesprayed water, and reaches the state represented with the point g. Thispoint is on the saturated liquid line on the Mollier chart, at atemperature of 30° C. and with an enthalpy of 109.99 kcal/kg.

The refrigerant in the state of point g is reduced in pressure with thethrottle 240, to 4.2 kg/cm² which is the saturation pressure at 10° C.,and, as a refrigerant liquid-gas mixture, reaches the cooler 210 (as anevaporator when seen from the refrigerant), takes heat from the processair, evaporates into the state of saturated gas of the point a on theMollier chart, drawn again into the compressor 260, and thereafter theabove-cycle is repeated.

As described above, in the heat exchanger 300, the state of therefrigerant changes from the point e to f because of evaporation in theevaporating section 251, and from the point f to g because ofcondensation in the condensing section 252. Since the changes areevaporation heat transfer and condensation heat transfer, the heattransfer efficiency is very high.

Furthermore, when the compression heat pump HP1 including the compressor260, the heater (refrigerant condenser) 220, the throttles 230, 240, andthe cooler (refrigerant evaporator) 210 is not provided with a heatexchanger 300, since the refrigerant in the state of point d in theheater (refrigerant condenser) 220 is returned to the cooler(refrigerant evaporator) 210, the differential enthalpy that can be usedin the cooler (refrigerant evaporator) 210 is only 25.86 kcal/kg(=148.83−122.97). In case the heat exchanger 300 is provided as in theembodiment of the invention, the differential enthalpy is 38.84 kcal/kg(=148.83−109.99), which means a decrease in the amount of gascirculating in the compressor 260 for the same cooling load, and in itsturn a decrease in the required power can be as much as 33%. That is tosay, the same effect as an economizer for taking in flash gas in amedium state is obtained though the compressor 260 is of a single stagetype or a multiple (for example two) stage type.

Referring to FIG. 7, another embodiment of a heat pump HP2 will bedescribed together with an explanation of another embodiment of adesiccant air conditioner incorporating the heat pump P2. Theconfiguration and function of the embodiment of FIG. 7 are the same asthose of FIG. 5 except water is used as the second fluid to flow throughthe second compartment of the heat exchanger 300 b used in place of theheat exchanger 300. As shown, cooling water cooled with a cooling tower470 installed outdoors to about 32° C. in summer is led to the intakeport of a cooling water pump 460 through a cooling water piping 471connected to the bottom portion of the cooling tower 470, and sent tothe second compartment of the heat exchanger 300 b through a coolingwater piping 472 connected the discharge port.

In the second compartment of the heat exchanger 300 b, the cooling watermeanders around obstruction plates provided at right angles to the heatexchanging tubes outside the heat exchanging tubes. A cooling waterpiping 473 is connected to the cooling water outlet of the secondcompartment so that the cooling water heated to a temperature raisedwith the heat exchanger 300 b is returned to the cooling tower. In thisway, in contrast to the embodiment of FIG. 5 in which the refrigerant iscondensed in the condensing section with the outside air, in thisembodiment the refrigerant is condensed in the condensing section withthe cooling water. Since the refrigerant cycle for the heat pump HP2 isthe same as that shown in FIG. 6, the explanation is not repeated.

Next, referring to FIG. 8, another embodiment of a heat pump HP3 will bedescribed together with explanation of another embodiment of a desiccantair conditioner incorporating the heat pump HP3. With this embodiment,since counterflow heat exchanging can be carried out between the firstand the second fluids, a heat pump or a dehumidifying air conditioner ofa high COP can be provided. The heat pump HP3 uses a heat exchanger 300c as shown schematically in FIG. 2(b) or FIG. 9. The heat exchanger 300c shown in FIG. 9 has basically the same configuration as that of theheat exchanger 300 shown in FIG. 1, except the former is not providedwith the water spray pipe 325, the nozzles 327, or the evaporatinghumidifier 165.

FIG. 8 is a flow chart of an air conditioning system including adesiccant air conditioner, a dehumidifying air conditioner, as anembodiment of the invention. FIG. 9 is a schematic cross sectional viewof an example heat exchanger as a process air cooler of the inventionfor use in the air conditioning system shown FIG. 8. FIG. 10 is arefrigerant Mollier chart for the heat pump HP3 included in the airconditioning system shown FIG. 8. FIG. 15 is a humid air chart for adehumidifying air conditioner as an embodiment of the invention.

The air conditioning system shown in FIG. 8 is to lower the humidity ofthe process air by means of a desiccant (drying agent) and to maintainan air conditioning space 101 to which the process air is supplied in acomfortable environment. In this embodiment, the path of the process airas the first fluid is the same as that shown in FIG. 5. That is, asshown, the devices are arranged along the path of the process air A fromthe air conditioning space 101, in the order of, the blower 102, thedesiccant wheel 103 filled with a desiccant and serving as a moistureadsorber, a process air cooler 300 c of the invention, and therefrigerant evaporator (as a cooler when seen from the refrigerant) 210,so that the process air returns to the air conditioning-space 101.

The outside air, first as the cooling fluid for the process air cooler300 c, is led from the outdoors OA along the path of the regenerationair B to the process air cooler 300 c, and secondly as the regenerationair through the refrigerant condenser (as a heater when seen from theregeneration air) 220, the desiccant wheel 103, and the blower 140 forcirculating the regeneration air, in that order, and discharged asexhaust EX outdoors.

Furthermore, along the refrigerant path from the refrigerant evaporator210, the compressor 260 for compressing the refrigerant made into thegas state by evaporation with the refrigerant evaporator, therefrigerant condenser 220, the header 235, a plurality of throttles230A, 230B, 230C branched off the header 235 and disposed parallel toeach other, the process air cooler 300 c, a plurality of throttles 240A,240B, 240C corresponding to the plurality of throttles 230A, 230B, 230C,and the header 245 for collecting flows from those throttles arearranged in that order, so that the flow returns to the refrigerantevaporator 210. The heat pump HP3 is constituted by including therefrigerant evaporator 210, the compressor 260, the refrigerantcondenser 220, a plurality of throttles 230A, 230B, 230C, the processair cooler 300 c, and the plurality of throttles 240A, 240B, 240C.

As described above, the heat exchanger 300 c for use in the heat pumpHP3 shown in FIG. 8 is provided with the throttles such as orificesdisposed between the header 235 and the evaporating section 251. Aplurality of evaporating sections 251A, 251B and 251C are respectivelyprovided with throttles 230A, 230B and 230C. Also the condensingsections 252A, 252B and 252C corresponding to the above-mentionedsections are provided with throttles 240A, 240B and 240C disposedbetween those sections and the header 245. Here, for example theevaporating section 251A corresponding to the throttle 240A is shown asa single tube in the drawing. However, a plurality of the tubes may beprovided side by side to increase their number in the direction normalto the drawing surface. That is, the throttle 240A may bundle a group ofevaporating sections. The same applies to other throttles 240B, 240C andcorresponding evaporating sections 251B, 251C.

With such a configuration, the process air A flows at right angles tothe heat exchange tubes in the first compartment so as to come intocontact with the evaporating sections 251A, 251B, and 251C in thatorder, and exchanges heat with the refrigerant. The outside air B withits inlet temperature being lower than that of the process air flows atright angles to the heat exchanging tubes in the second compartment soas to come into contact with the condensing sections 252C, 252B and 252Ain that order. In such a case, while the evaporation pressures(temperatures) or condensation pressures (temperatures) are determinedfor each group of sections provided with throttles, they are arranged inthe high to low order of 251A, 251B and 251C in the evaporating section,and in the low to high order of 252C, 252B and 252A in the condensingsection. That is, the refrigerant of the process air cooler 300 c coolsthe process air A at a plurality of evaporation pressures, and therefrigerant is cooled and condensed with the outside air B as a coolingfluid at a plurality of condensing pressures corresponding to theevaporating pressures. Those evaporation pressures and condensationpressures are arranged in the high to low or low to high order.

In this way, when the flows of the process air A and the outside air Bare noted, both of the flows exchange heat by the so-calledcounterflows, which achieves an extremely high heat exchange efficiencyΦ, for example 80% or higher.

Here, how the plurality of evaporation pressures are arranged in thehigh to low order will be further described. The evaporation pressuresin the plurality of evaporating sections 251A, 251B and 251C can beindependent or different from each other as a result of providingrespective sections with respectively independent throttles 230A, 230Band 230C. When the process air is made to flow through the firstcompartment so as to come into contact successively with the evaporatingsections 251A, 251B and 251 c in that order, the process air is deprivedof its sensible heat and its temperature decreases along its flow fromthe inlet to the outlet. As a result, the evaporation pressures in theevaporating sections 251A, 251B and 251C decrease and are arranged inthat order from high to low.

Quite likewise, the condensation temperatures are arranged in the low tohigh order of 252C 252B and 252A. Like the evaporating sections, sincethe respective condensing sections are provided with mutuallyindependent throttles 240A, 240B and 240C, the respective condensingsections can have mutually independent condensation pressures andmutually independent condensation temperatures. When the outside air ismade to flow through the second compartment from its inlet to outlet soas to come into contact successively with the condensing sections 252C,252B and 252A in that order, the condensation pressures are arranged inthat order from low to high. Therefore, when the flows of the processair A and the outside air B are noted as described before, they form aso-called counterflow type of heat exchanger to achieve a high heatexchange efficiency. Here, the evaporating section 251A and thecondensing section 252A may be constituted with mutually independentheat pipes, and the same constitution applies to the evaporating section251B and the condensing section 252B, and to the evaporating section251C and the condensing section 252C. Still, the same function isobtained that the heat can be exchanged in counterflow manner.

In the process air cooler 300 c shown in FIG. 9, the first compartment310 and the second compartment 320 are disposed side by side on bothsides of the partition plate 301, and the evaporating section and thecondensing section are formed by an integral, continuous tube. However,the heat exchanger may also be configured as shown in FIG. 3 in whichthe first compartment 310 and the second compartment 320 and also thefirst and the second flow passages are disposed separately. In otherwords, in such a configuration, the evaporating sections 251A, 251B and251C are respectively connected to corresponding condensing sections252A, 252B and 252C through an appropriate header and connection piping.In that case, the function of the heat exchanger also remains unchangedfrom that shown in FIG. 9. However, versatility in positioning ofdevices increases as a result of separation of the first and the secondcompartments 310 and 320.

The header 245 on the condensing section 252 side is connected to therefrigerant evaporator (as a cooler when seen from the process air) 210through the refrigerant liquid piping 203. While the attachmentpositions of the throttles 240A, 240B and 240C may be anywhere betweenjust after the condensing sections 252A, 252B and 252C and the inlet ofthe refrigerant evaporator 210, preferably they are just before theinlet of the refrigerant evaporator 210. The reason is that theinsulation for the piping for the refrigerant after the throttles 240A,240B and 240C where the refrigerant becomes considerably colder than theatmosphere may be made thinner. The refrigerant liquid condensed in thecondensing sections 252A, 252B and 252C is cooled to lower temperaturesby pressure reduction and expansion, enters and evaporates in therefrigerant evaporator 210 to cool the process air by the evaporationheat. The throttles 230A, 230B and 230C, and 240A, 240B and 240C may befor example orifices, capillary tubes, expansion valves, or the like.

Here, the throttles 240A, 240B and 240C are usually orifices or the likeof a constant opening. Apart from those constant opening throttles, itmay also be configured such that an expansion valve 270 is disposedbetween the header 245 and the refrigerant evaporator 210, and also atemperature sensor (not shown) is disposed at the refrigerant outlet ofthe refrigerant evaporator 210 or in the heat exchanging portion of therefrigerant evaporator 210 to detect the superheat temperature and toregulate the opening of the expansion valve 270. In this way, therefrigerant is prevented from being supplied in an excessive amount tothe refrigerant evaporator 210, and the refrigerant liquid that has beenleft out of evaporation is prevented from being drawn into thecompressor 260.

The refrigerant evaporated into the gaseous state in the refrigerantevaporator 210 is led to the intake side of the refrigerant compressor260, and the above-described cycle is repeated thereafter.

In the embodiment shown in FIG. 8, the outside air as the second fluidis used as the regeneration air for regenerating the desiccant. Asshown, a duct 124 is connected to the inlet of the second compartment320 to introduce outside air from outdoors OA. The outside airintroduced through the duct 124 enters the second section 320 and, whileflowing through the section, takes heat from the refrigerant in thecondensing section 252 and causes the refrigerant to condense. Here, thecondensing section 252 is constituted to include sections 252C, 252B and252A with their condensation temperatures arranged in that order fromlow to high. Therefore, the outside air exits the second compartment 320after contacting the condensing section 252A of the highest temperature.The outlet of the second compartment 320 is connected through a duct 126to the heater 220. The outside air heated to a certain extent in thesecond compartment 320 is led to the heater 220, additionally heatedthere, and as the regeneration air reaches the desiccant wheel 103through a duct 127 which interconnects the heater 220 and the desiccantwheel 103.

As described above, the regeneration air introduced into the desiccantwheel 103, after heating to regenerate the desiccant, is dischargedthrough ducts 128 and 129 leading from the desiccant wheel 103 to theoutside air. The blower 140 is disposed between the ducts 128 and 129 todraw in outside air, and to flow it through the regeneration air path.

Next, the path of the refrigerant will be described. As shown, therefrigerant gas compressed with the refrigerant compressor 260 is ledthrough a refrigerant gas piping 201 connected to the outlet of thecompressor to the regeneration air heater (as a condenser when seen fromthe refrigerant) 220. The refrigerant gas compressed with the compressor260 is at a higher temperature due to compression heating, and the heatis used to heat the regeneration air. The refrigerant gas itself losesheat and condenses.

A refrigerant piping 202 is connected to the refrigerant outlet of theheater 220 to further lead to the header 235 where it is divided into aplurality (three in FIG. 8) of refrigerant branches respectivelyprovided with throttles 230A, 230B and 230C. The throttles 230A, 230Band 230C are respectively connected to the evaporating sections 251A,251B, and 251C. Therefore, it is configured such that evaporation occursat different pressures or in turn at different temperatures respectivelyin the evaporating sections 251A, 251B and 251C. The throttles 230A,230B and 230C are respectively disposed in the vicinities of theevaporating sections 251A, 251B and 251C. The throttles may be in theform of orifices, capillary tubes, expansion valves, or the like. WhileFIG. 8 shows only three throttles, they may be provided in any number,two or more, according to the number of the evaporating sections 251 andthe condensing sections 252.

The refrigerant liquid coming out of the heater (refrigerant condenser)220 is reduced in pressure and expanded with the throttles 230A, 230Band 230C, and part of it evaporates (flashes). The refrigerant in thestate of liquid-gas mixture reaches the evaporating sections 251A, 251Band 251C and flows there so as to wet the inside walls of the tubes ofthe evaporating section, evaporates, and cools the process air flowingthrough the first compartment 310.

Each of the evaporating sections 251A, 251B and 251C and each of thecondensing sections 252A, 252B and 252C are respectively constitutedwith a series of tubes, namely as individual flow passages, so that therefrigerant that has evaporated (and that has not evaporated) flows intothe condensing sections 252A, 252B and 252C and is deprived of its heatwith the outside air flowing through the second compartment andcondenses.

The outlet sides of the condensing sections 252A, 252B and 252C arerespectively provided with throttles 240A, 240B and 240C. Beyond thethrottles 240A, 240B and 240C is disposed the header 245 to which isconnected the refrigerant piping 203 so as to lead the refrigerant tothe cooler 210.

With such a constitution, the refrigerant liquid condensed in thecondensing sections 252A, 252B and 252C is cooled by reduction inpressure and expansion with the throttles 240A, 240B and 240C andcollected in the header 245, enters and evaporates in the cooler 210 tocool the process air by its evaporation heat.

Next, referring to FIG. 10, the function of the heat pump HP3 will bedescribed. FIG. 10 is a Mollier chart when a refrigerant HFC134 a isused. In this chart, the horizontal axis represents enthalpy, and thevertical axis represents pressure.

As shown, the point a corresponds to the state at the refrigerant outletof the cooler 210 shown in FIG. 8, in a saturated gas state. In theexample shown, the pressure is 4.2 kg/cm² as the third pressure or a lowpressure, the temperature is 10° C., and the enthalpy is 148.83 kcal/kg.This gas is drawn in and compressed with the compressor 260 and thestate of the gas at the outlet of the compressor 260 is shown at thepoint b. In this state, the pressure is 19.3 kg/cm² and the temperatureis 78° C.

The refrigerant gas is cooled in the heater (refrigerant condenser) 220and reaches the state represented by the point c on the Mollier chart.This point represents a saturated gas state with a pressure of 19.3kg/cm² as a first pressure or a high pressure, and a temperature of 65°C. Further cooling and condensation under this pressure leads to thestate of point d. This point represents a saturated liquid state withthe same pressure and the temperature as those at the point c, namely19.3 kg/cm² and 65° C., and with an enthalpy of 122.97 kcal/kg.

The state of part of the refrigerant reduced in pressure with thethrottle 230A and flowed into the evaporating section 251A isrepresented with the point e1 on the Mollier chart. Its temperaturebecomes 43° C. Its pressure is one of a plurality of different pressures(second pressure) of the invention and a saturation pressurecorresponding to the temperature of 43° C. Similarly, the state of therefrigerant reduced in pressure with the throttle 230B and has flowedinto the evaporating section 251B is represented with the point e2 onthe Mollier chart. Its temperature becomes 40° C. Its pressure is one ofa plurality of different pressures (second pressure) of the inventionand a saturation pressure corresponding to the temperature of 40° C.Likewise, the state of the refrigerant reduced in pressure with thethrottle 230C and flowed into evaporating section 251C is shown by thepoint e3 on the Mollier chart, with a temperature of 37° C. and asaturation pressure corresponding to the temperature of 37° C. as one ofthe plurality of different pressures of the invention.

At whichever of the points e1, e2 or e3, the refrigerant is located,part of the refrigerant liquid evaporates (flashes) and is in the stateof mixture of liquid and gas. In each of the evaporating sections, therefrigerant evaporates under one of the plurality of different pressuresand respectively reach intermediate points f1, f2 and f3 between thesaturated liquid line and the saturated vapor line for respectivepressures.

The refrigerant in those states flows into the respective condensingsections 252A, 252B, and 252C. In each condensing sections, therefrigerant is deprived of its heat with the outside air flowing throughthe second compartment and respectively reaches the points g1, g2, andg3. These points are on the saturated liquid line on the Mollier chart.Their temperatures are 43° C., 40° C., and 37° C., respectively. Theserefrigerant liquids reach the points j1, j2, and j3 through respectivethrottles. The pressure at these points is 4.2 kg/cm², the saturationpressure for 10° C.

Here, the refrigerant is in the state of a mixture of liquid and gas.These refrigerants flow into the single header 245 and the enthalpy ofthe joined flow is an average of the enthalpy values at the points g1,g2, and g3 respectively weighted with the corresponding flow rates ofthe refrigerant. In this embodiment, the value is approximately 113.51kcal/kg. Even though it is 3-layered, the reason for the higher enthalpythan in the case shown in FIG. 6 is that water is not sprayed in thesecond compartment.

The refrigerant evaporates as it takes heat from the process air in thecooler (refrigerant evaporator) 210 to be in the state of point a on theMollier chart and drawn into the compressor 260 again, and thereafterthe above-described cycle is repeated.

As described above, the refrigerant evaporates in each evaporatingsection and condenses in each condensing section in the heat exchanger300 c. Since heat is transferred by evaporation and condensation, theheat transfer efficiency is extremely high. Moreover, since the processair flowing downward from the upper part of the first compartment 310 inthe drawing is cooled from a higher to a lower temperature attemperatures arranged in the high to low order of 43° C., 40° C., and37° C., heat exchange efficiency is higher in comparison with the caseof cooling at a single temperature of, for example, 40° C. The same istrue for the condensing section. That is, in the second compartment 320,since the outside air (regeneration air) is heated from a lower to ahigher temperature as the air flows up from the lower part in thedrawing at temperatures arranged in the low to high order of 37° C., 40°C. and 43° C., heat exchange efficiency is higher in comparison with thecase of heating at a single temperature of, for example, 40° C.

Furthermore, when the compression heat pump HP3 including the compressor260, the heater (refrigerant condenser) 220, the throttles 230, 240, andthe cooler (refrigerant evaporator) 210 is not provided with a heatexchanger 300C, since the refrigerant in the state of point d in theheater (refrigerant condenser) 220 is returned to the cooler(refrigerant evaporator) 210, the differential enthalpy that can be usedin the cooler (refrigerant evaporator) 210 is only 25.86 kcal/kg. Incase that the heat exchanger 300C is provided as in this embodiment ofthe invention, the differential enthalpy is 35.32 kcal/kg(=148.83−113.51), which means a decrease in the amount of gascirculating in the compressor 260 for the same cooling load, and in itsturn a decrease in the required power by as much as 27%. On the otherhand, the cooling effect that can be accomplished with the identicalpower can be improved by as much 37%. That is to say, the same effect asan economizer for taking in flash gas in a medium state is obtainedwhether the compressor 260 is of a single stage type or a multiple (forexample two) stage type, in the same manner as the embodiment described,referring to FIG. 5 or 7. Therefore, high COP can be achieved. Thefunction of the dehumidifier of this embodiment using a humid chart willbe described later referring to FIG. 15.

Next, referring to FIG. 11, another embodiment of a heat pump HP4 willbe described together with explanation of another embodiment of adesiccant air conditioner incorporating the heat pump HP4. With thisembodiment, since the refrigerant supplied to the second heat exchanger(process air cooler) for exchanging heat between the first and thesecond fluids is separated into vapor phase and liquid phase before therefrigerant flows into the second heat exchanger, heat exchange becomesuniform, thus making it possible to provide a heat pump or adehumidifying air conditioner of a high COP. FIG. 12 shows theconstitution of a heat exchanger 300 d as the second heat exchangersuitable for use in the heat pump HP4. FIG. 13 is a Mollier chart forexplaining the refrigerant cycle of the heat pump HP4.

Since the path of the process air, the path of the regeneration air, andthe path of the cooling fluid are the same as those of the airconditioner as shown in the embodiment FIG. 5, explanations will notrepeated.

Here, the path of the refrigerant of the heat pump HP4 will bedescribed. As shown, the refrigerant gas compressed with a refrigerantcompressor 260 is drawn to a regeneration air heater 220 through arefrigerant gas piping 201 connected to the outlet of the compressor260. The temperature of the refrigerant gas compressed with thecompressor 260 is increased by the heat of compression which in turnheats the regeneration air. The refrigerant gas itself condenses as itis deprived of its heat.

The refrigerant outlet of the heater 220 is connected to the inlets ofthe evaporating sections 251A, 251B and 251C of the heat exchanger 300 dthrough a refrigerant passage 202. The throttle 360 in the form of anexpansion valve or the like is provided in the middle of the refrigerantpassage 202. A vapor-liquid separator 350 is provided between thethrottle 360 and evaporating sections 251A, 251B and 251C. Theconstitution of the heat exchanger 300 d will be described later indetail referring to FIG. 12.

Liquid refrigerant coming out of the heater 220 is reduced in pressurewith the expansion valve 360 as the first throttle, expands, and part ofthe liquid refrigerant evaporates (flashes). The liquid-vapor mixture ofrefrigerant is separated into vapor and liquid with the vapor-liquidseparator 350, the refrigerant liquid reaches the evaporating sections251A, 251B and 251C, evaporates in the tubes of the evaporating sections251A, 251B and 251C, and cools the process air flowing through the firstcompartment 310.

The evaporating section 251 and the condensing section 252 constitute acontinuous tube. That is, since they constitute a single flow passage,the refrigerant that has evaporated (and that has not evaporated) flowsinto the condensing section 252, and is deprived of its heat with theoutside air flowing through the second compartment, then condenses.However, it is also possible to constitute the first and the secondcompartments separately, and to constitute the evaporating andcondensing sections separately. In that case, the evaporating andcondensing sections maybe communicated with each other, for examplethrough piping.

The outlet side of the condensing section 252 is connected through therefrigerant liquid piping 203, the expansion valve 270 as the secondthrottle, and another refrigerant liquid piping 204 to the cooler 210.The refrigerant that has condensed in the condensing section 252 isreduced in pressure with the throttle 270, cooled by expansion,evaporates as it enters the cooler 210 (as an evaporator when seen fromthe refrigerant side), and cools the process air with its evaporationheat. The throttles 360 and 270 may be for example orifices, capillarytubes, as well as expansion valves.

The refrigerant evaporated into the gaseous state in the cooler 210 isled to the intake side of the refrigerant compressor 260, and thereafterthe above-described cycle is repeated.

The vapor-liquid separator 350 is configured to include a container intowhich vapor-liquid mixture flows, and an obstruction plate 355 placed toface the inflow of the vapor-liquid mixture. When the vapor-liquidmixture strikes the obstruction plate 355, the liquid is separated fromthe vapor, the vapor flows out of a vapor outlet provided side by sidewith the vapor-liquid mixture inlet, and flows to the heat exchanger 300d through a refrigerant piping 340 connected to the vapor outlet. Therefrigerant liquid flow out of a liquid outlet disposed in a positionvertically below the container of the vapor-liquid separator. To theliquid outlet are connected liquid piping 430A, 430B and 430Crespectively communicating with the evaporating sections 251A, 251B and251C.

Referring to FIG. 12, the constitution of the heat exchanger 300 d asthe second heat exchanger suitable for use in the heat pump HP4 as anembodiment of the invention will be described. The heat exchanger 300 dcan be used in place of the heat exchanger 300 in the heat pump HP1described referring to FIG. 5. As shown, the heat exchanger 300 d issimilar to the heat exchanger shown in FIG. 1 in that the firstcompartment 310 for flowing the process air A as the first fluid and thesecond compartment 320 for flowing the outside air B as the second fluidare disposed adjacent to each other through a single partition wall 301.

Also, the positioning of the evaporating sections 251A, 251B and 251C,condensing sections 252A, 252B and 252C, water spray pipe 325,evaporation humidifier 165, process air passages 109, 110, and outsideair passage 171 are similar to those of the heat exchanger shown in FIG.1.

The evaporating sections 251A, 251B and 251C are connected to headers450A, 450B and 450C respectively connected to refrigerant piping 430A,430B and 430C. Each of the evaporating sections 251A, 251B and 251C isconstituted with a plurality of (six in the example of FIG. 12) heatexchange tubes joined to each of the headers 450A, 450B and 450C.

A refrigerant vapor piping 340 passes through the first compartment 310of the heat exchanger 300 d through a tube 341. The tube 341 is disposedto pass through the partition wall 301 and further through the secondcompartment 320. In the example shown in FIG. 12, two parallel tubes 341are disposed, with each tube passing through the 35 second compartment320 three times. Here, part of the tube 341 within the secondcompartment 320 is provided with fins attached to the outer side of thetube to accelerate heat exchange in the same manner as in the condensingsections 252A, 252B and 252C. That part is referred to as the condensingsection 252D. The condensing section 252D is disposed in a position onthe upstream side of the outside air flow in the condensing section 252Cand between the condensing section 252C and the evaporation humidifier165. In the condensing section 252D, the refrigerant vapor is deprivedof its heat with the second fluid or the outside air and condenses.Incidentally, the condensing section 252D may be disposed on thedownstream side of the outside air flow in the condensing section 252A.

Since the tube 341 scarcely contributes to the heat exchange in thefirst compartment 310, the tube 341 practically bypasses the firstcompartment 310. Therefore, the tube 341 may be routed to bypass thefirst compartment 310 in actual constitution, in other words, the tube341 is routed outside the first compartment 310 and connected to thecondensing section 252D in the second compartment.

The refrigerant liquid outlet sides of the condensing sections 252A,252B and 252C are respectively provided with headers 455A, 455B and 455Cto bring together the condensing sections 252A, 252B and 252C that eachis constituted with a plurality of tubes. Tubes from respective headersare further brought together with a header 370 (FIG. 11) which in turnis connected to the expansion valve 270 as described above through therefrigerant piping 203. The refrigerant liquid from the condensingsection 252D is drawn out through a refrigerant piping 345 connected tothe condensing section 252D and joins the passage 203 on the downstreamside of the header 370. Incidentally, the piping 345 may be connected tothe header 370.

Referring to the Mollier chart of FIG. 13, the function of the heat pumpHP4 as an embodiment of the invention will be described. The Mollierchart of FIG. 13 is for the use of the refrigerant HFC 134 a, with thehorizontal axis indicating enthalpy and the vertical axis indicatingpressure.

In the drawing, the points a, b, c and d are the same as those in theMollier chart of FIG. 6 and so their explanations are omitted. Therefrigerant liquid in the state of the point d is reduced in pressurewith the throttle 360 and flows into the vapor-liquid separator 350.Then, the separated refrigerant vapor flows through the piping 340 intothe tube 341 as a vapor in the state of the point h where the isobaricline of the saturation pressure corresponding to 40° C. intersects thesaturated vapor line, and flows into the condensing section 252D. Therethe vapor condenses as its heat is taken with the outside air (that iscooled with the water from the spray pipe and the evaporationhumidifier), reaches the saturation liquid line or typicallysupercooled, and reaches the point i beyond the saturated liquid line.

The liquid separated with the vapor-liquid separator 350 is in the stateof the intersection e between the saturated liquid line and the isobaricline of the saturation pressure corresponding to 40° C. This liquidevaporates in the evaporating section 251 as it reaches the point f,then condenses in the condensing section 252 to be in the liquid stateof point g. The liquid in the state of the point i and the liquid in thestate of the point g are mixed together in the header 370, and reducedin pressure in the expansion valve 270 to be the refrigerant(vapor-liquid mixture) of a pressure of 42.2 kg/cm² and a temperature of10° C.

As described above, in this embodiment, almost no vapor-phase content iscontained in the refrigerant led to the heat exchange tubes (heattransfer pipe) constituting the evaporating sections 251A, 251B and 251Cof the second heat exchanger 300 d. As a result, the amount of therefrigerant led to the evaporating sections 251A, 251B and 251C becomesuniform, the process air as the first fluid is cooled uniformly by theevaporation in the evaporating sections 251A, 251B and 251C, and theamount of refrigerant that condenses on the heat transfer pipe of thecondensing sections 252A, 252B and 252C is made up of the refrigerantthat has evaporated in the evaporating sections 251A, 251B and 251C. Ifthe vapor phase is contained, the heat transfer lacks uniformity sincethe condensation amount in the condensing section that contains vaporphase is especially large. However, if the liquid phase only is present,such a problem does not occur.

In this way, the amount of heat transferred by the heat pipe function(change in refrigerant phase, especially the heat transfer function byevaporation and condensation) of the heat transfer pipe is made uniformfrom one heat transfer pipe to another, heat transfer is made uniform inthe entire heat exchanger 300 d. As a result, an undesirable situationis prevented, namely the air as the first and the second fluid isprevented from passing through without contributing to the heattransfer. Therefore, the dehumidifying air conditioner as an embodimentprovided with the heat pump HP4 makes it possible to improve the heatexchange efficiency between the first fluid, the process air, and thesecond fluid, the cooling medium (outside air) or the regeneration air,and to improve functional reliability.

An embodiment of the invention will be hereinafter described withspecific numerical values. Calculating conditions are assumed that; theheat transfer amount is 2 USRt, the evaporation temperature is 10° C.,the economizer temperature (saturation temperature corresponding to thesecond pressure) is 40° C., the condensation temperature is 65° C., therefrigerant is HFC 134 a, and the pipe diameter is 12 mm. Also assumedthat; the inside diameter of the heat transfer pipe is 8.3 mm, and thenumber of the heat transfer pipe is 40 (in case of three tiers as shownin FIG. 12, for example 13, 14, and 13 pipes are disposed in respectivetiers in a staggered pattern). Here, the refrigerant circulation amountis calculated by reading the enthalpy values of the points on theMollier chart of FIG. 13 as:

2×3024/(138.83−113.51)=171.23 kg/h=0.0476 kg/s.

Comparative Example

The refrigerant in vapor-liquid phase after being expanded in theexpansion valve is branched into a large number of heat transfer pipesconstituting a single pass of the heat exchanger. Since the heattransfer pipes have to be disposed in a single pass in the second heatexchanger, the number of branches increases.

Dryness immediately after expansion valve: (122.97−113.51)/39.42=0.242(The value 39.42 is the enthalpy difference between points h and e or gin FIG. 13.)

Specific volume of two-phase mixture refrigerant immediately afterexpansion valve: 0.00087261×(1−0.242)+0.020032×0.242=0.00551 m³/kg

Flow velocity 1 (in three piping of 12 mm diameter):0.0051×0.0476×4/(0.012×0.012×3.14×3)=0.773 m/s

Flow velocity 2 (in 40 heat transfer pipe of 8.3 mm diameter):0.0051×0.0476×4/(0.0083×0.0083×3.14×40)=0.121 m/s

At the flow velocity 1, the refrigerant flows through the pipe in thestate of almost uniform vapor-liquid mixture. At the flow velocity 2 inthe branched heat transfer pipes, since the velocity is too slow, therefrigerant is separated by gravity into two, vapor and liquid phases,with the vapor phase flowing on the upper side while the liquid phaseflowing on the lower side. In this way, since the flow velocity becomesextremely slow after branching, it is difficult to distribute the vaporphase refrigerant in the state of being uniformly mixed with the liquidphase refrigerant. This in turn results in that, since the situations ofthe flow are different before and after the branching, the refrigerantcannot be distributed uniformly.

Embodiment

Dryness immediately after expansion valve: 0

Specific volume of liquid refrigerant immediately after expansion valve:0.00087261 m³/kg

Flow velocity 3 (in three pipes of 12 mm diameter):0.00087261×0.0476×(1−0.242)×4/(0.012×0.012×3.14×3)=0.0928 m/s

Flow velocity 4 (in 40 heat transfer pipes of 8.3 mm diameter):0.00087261×0.0476×(1−0.242)×4/(0.0083×0.0083×3.14×40)=0.0146 m/s

In this way, since both of the flow velocities 3 and 4 are slow and thatthe refrigerant in liquid phase only flows, the refrigerant is uniformlydistributed to the heat transfer tubes.

The above embodiment is described for the case in which the outside airis cooled by the evaporation heat of water using the evaporationhumidifier and the water spray pipe and the air is used as the secondfluid. However, it is also possible to have a constitution in which,like the third embodiment shown in FIG. 8, the regeneration air isheated in the second compartment.

With the invention described above, since the second heat exchanger thatcauses the refrigerant to evaporate and also to condense under thesecond pressure which is lower than the first pressure is provided, theenthalpy difference per unit amount of refrigerant can be increased.Therefore, it is possible to provide a heat pump capable of increasingthe enthalpy difference per unit amount of refrigerant and accordinglycapable of highly improving the COP.

Therefore, if the heat pump of the invention is used as the heat sourceof a desiccant air conditioner for example, it is possible to greatlyincrease the efficiency of the desiccant air conditioner.

When the second heat exchanger is provided with a vapor-liquidseparator, since the refrigerant vapor is separated from the refrigerantliquid, heat exchange in the second heat exchanger is uniform.

A dehumidifying air conditioner of the invention will be hereinafterdescribed referring to FIG. 14 for its function, and referring to FIG. 5as appropriate for its constitution. In FIG. 14, conditions of air invarious portions are indicated with letters D, E, K to N, and Q to X.These letters correspond to those in circles shown in the flow chart ofFIG. 5.

First, the flow of the process air A will be described. In FIG. 14, theprocess air (state K) is drawn in from the space to be air-conditioned,or the conditioning space 101 through the process air passage 108 bymeans of the blower 102, and sent into the desiccant wheel 103. Here,the air is deprived of its moisture with the desiccant disposed in thedrying element 103 a (FIG. 16, to be explained later) or made to be of alower absolute humidity and reaches the state L of a higher dry bulbtemperature due to the adsorption heat of the desiccant. This air issent through the process air passage 109 to the first compartment of theprocess air cooler 300. There the air, while remaining at a constantabsolute humidity, is cooled with the refrigerant evaporating in theevaporating section 251 (Fig.) to be in the state M, and enters thecooler 210 through the passage 110. Here, the air, also remaining at aconstant absolute humidity, is further cooled to the state N. This air,as the process air SA that has been dried and cooled to appropriatehumidity and temperature, is returned through the duct 111 to the airconditioning space 101.

Next, the flow of the regeneration air B will be described. In FIG. 14,the regeneration air (state Q) is drawn in from outdoors OA through theregeneration air passage 124 to the heat exchanger 121. Here, theintroduced air exchanges heat with the higher temperature regenerationair to be discharged (air in the state U to be described later) to raisethe dry bulb temperature, and reaches the state R. This air is sentthrough the passage 126 to the refrigerant condenser (as a heater whenseen from the regeneration air) 220 where the air is heated to a higherdry bulb temperature, and reaches the state T. This air is sent throughthe passage 127 to the desiccant wheel 103 where the air removesmoisture from the desiccant in the drying element 103 a (FIG. 16) toregenerate the desiccant. As the air adsorbs the moisture, the absolutehumidity of the air increases, the dry bulb temperature decreases due tothe water adsorption heat of the desiccant, and the air reaches thestate U. This air is drawn through the passage 128 into the blower 140for circulating the regeneration air and sent through the passage 129into the heat exchanger 121, and as described before, exchanges heatwith the regeneration air (air in the state Q) that is not yet sent intothe desiccant wheel, and the air itself becomes cooler in the state V,and discharged EX through the passage 130.

Next, the flow of the outside air C as a cooling fluid will bedescribed. The outside air C (in the state Q) from outdoors OA is sentthrough the passage 171 into the second compartment 320 of the processair cooler 300. There, first the air absorbs moisture in the humidifier165 and brings about a higher absolute humidity through iso-enthalpychange while bringing about a lower dry bulb temperature, and reachesthe state D. The state D is approximately on the saturation line in thehumid vapor chart. This air cools the refrigerant in the condensingsection 252 while further absorbing moisture supplied through the waterspray piping 325 in the second compartment 320. This air changesapproximately along the saturation line to a higher absolute humidityand a higher dry bulb temperature, reaches the state E, and isdischarged EX through the passage 172 with the blower 160 disposed inthe middle of the passage 172.

In further reference to FIG. 14 here, functions of the humidifier 165and the, water spray piping 325 will be described. With the airconditioner described above, as will be understood from the cycle on theair side shown on the humid air chart of FIG. 14, when it is assumedthat; the amount of heat imparted to the regeneration air forregenerating the desiccant in the humidifier is ΔH, the amount of heatpumped up from the process air is Δq, and the driving energy of thecompressor is Δh, then ΔH=Δq+Δh. A cooling effect ΔQ obtained as aresult of regeneration with the heat amount ΔH is greater as thetemperature of the outside air (state Q) for exchanging heat with theprocess air after moisture adsorption (state L) is lower. That is, thegreater the ΔQ−Δq, the greater ΔQ. Therefore, spraying water, etc. tothe outside air as the cooling fluid is effective to improve coolingeffect. In FIG. 14, the points denoted by the states M′ and N′ indicatehow the states M and N would change if the evaporation humidifier 165and the water spray piping 325 were not used.

An embodiment of the invention will be described referring to FIG. 15for its function, and Referring to FIG. 8 as appropriate for itsconfiguration. In FIG. 15, conditions of air at various points areindicated with letter symbols K to N, Q, R, X, T and V. These lettersymbols correspond to those in circles shown in the flow chart of FIG.8.

Since the flow of the process air A is the same as in the case of FIG.14, the explanation therefor is not repeated. However, the process aircooler through which the process air passes is shown as 300 c, andtherefore, its details are different in some points as shown in FIG. 9.

Next, the flow of the regeneration air will be described. In FIG. 15,the regeneration air (state Q) is introduced from outdoors OA throughthe regeneration air passage 124 to the second compartment 320 of theprocess air cooler 300 c. Here, the introduced air exchanges heat withthe condensing refrigerant to raise the dry bulb temperature, andreaches the state R. This air is sent through the passage 126 to therefrigerant condenser (as a heater when seen from the regeneration air)220 where the air is heated to a higher dry bulb temperature, andreaches the state T. This air is sent through the passage 127 to thedesiccant wheel 103 where the air removes moisture from the desiccant inthe drying element 103 a (FIG. 16) to regenerate the desiccant. As theair adsorbs the moisture, the absolute humidity of the air increases,the dry bulb temperature decreases due to the moisture adsorption heatof the desiccant, and the air reaches the state U. This air is drawnthrough the passage 128 into blower 140 for circulating regeneration airand discharged EX through the passage 129.

With the air conditioner described above, the relation among the amountof heat ΔH, the amount of heat Aq pumped from the process air, and thedriving energy Δh of the compressor shown in the cycle on the air sideon the humid air chart of FIG. 15 is the same as that explainedReferring to FIG. 14, and thus, ΔH=Δq+Δh. With this embodiment, sincethe heat exchange efficiency of the process air cooler 300 c is veryhigh, cooling effect can be enhanced remarkably.

As described above, since the heat pump or the dehumidifying device ofthis invention is configured such that it includes the process aircooler, that the process air cooler cools the process air by theevaporation of the refrigerant, and that the evaporated refrigerant iscooled and condensed with the cooling fluid, it is possible to utilizeevaporating heat transfer and condensing heat transfer both having highheat transfer coefficients and to carry out heat transfer between theprocess air and the cooling fluid with a high rate of heat transfer.Since the heat transfer between the process air and the cooling fluid iseffected through the refrigerant, component layout of the dehumidifyingair conditioner is facilitated. Moreover, a plurality of refrigerantevaporating pressures are used, and also a plurality of condensingpressures are used corresponding to the evaporation pressures for therefrigerant that is cooled and condensed with the cooling fluid, and theevaporating pressures are typically arranged in the high to low order.That is to say, in the case of the evaporation temperatures beingarranged in the high to low order, the heat exchange between the processair and the cooling fluid can be effected in the so-called counterflowmanner. This in turn makes it possible to provide a dehumidifying airconditioner having a high COP and a compact configuration.

When the heat pump is configured to include the refrigerant evaporator,the compressor, and the condenser, and is further constituted to supplythe refrigerant condensed with the condenser to the process air cooler,the same refrigerant used in the process air cooler can also be used inthe heat pump, and the COP of the heat pump increases. As a result, itis possible to enhance the efficiency of the dehumidifying airconditioner remarkably.

Referring to FIG. 16, a desiccant wheel as a moisture adsorber suitablefor use in the dehumidifying air conditioner as an embodiment of theinvention will be herein after described. As shown,the desiccant wheel103 is formed as a thick disk-shaped wheel for rotation about a rotationaxis AX, filled with a desiccant having gaps for permitting passage ofgas. It is constituted for example with a bundle of a plurality oftubular drying elements 103 a with their axes parallel to the rotationaxis AX. This wheel is configured such that it rotates in one directionabout the rotation axis AX and that the process air A and theregeneration air B flow in and out parallel to the rotation axis AX. Thedrying elements 103 a are disposed to come into contact with the processair A and the regeneration air B by turns as the wheel 103 rotates.Incidentally in FIG. 16, the outer circumferential portion of thedesiccant wheel 103 is shown as partially broken away. While FIG. 16seems to show gaps between the outer circumferential portion of thewheel 103 and part of the drying elements 103 a, actually the dryingelements 103 a are tightly packed as a bundle in the wheel 103.Generally the process air (A, indicated with white arrows in thedrawing) and the regeneration air (B, indicated with black arrows in thedrawing) are arranged to flow parallel to the rotation axis AX incounterflow manner to each other, each flowing through about each halfof the circular compartment of the desiccant wheel 103. The flowpassages of the process air and the regeneration air are divided with anappropriate partition plate (not shown) so that both of the flows do notmix with each other.

It is possible that a desiccant material is packed into the tubulardrying elements 103 a, that the tubular elements 103 a themselves aremade of the desiccant material, that the drying elements 103 a arepainted with the desiccant material, or that the drying elements 103 aare made of a porous material and impregnated with the desiccantmaterial. Each of the drying elements 103 a may be formed in the tubeshape of a circular cross section as shown, or in the tube shape of ahexagonal cross section to be bundled together into a honeycombstructure. In any case, it is configured such that the air flows in thethickness direction of the disk-shaped wheel 103.

Since the heat exchanger 121 (Refer to FIGS. 5, 7 and 11) has to pass alarge amount of regeneration air, the heat exchanger is a conventionallyused cross-flow type of heat exchanger for example as shown in FIG. 49for flowing the regeneration air B1 of a low temperature and theregeneration air B2 of a high temperature at right angles to each other,or a rotary type heat exchanger which is similar in constitution to thedesiccant wheel shown in FIG. 16 and is filled with a heat storingmaterial of a large thermal capacity in place of the drying elements. Inthat case, the low temperature regeneration air B1 corresponds to theprocess air A of FIG. 16, and the high temperature regeneration air B2corresponds to the regeneration air B.

Next, referring to the table of FIG. 17, the operation modes of thedehumidifying air conditioner as an embodiment of the invention, whichis explained above, referring to FIG. 5, and functions of its variousdevices will be described. As shown in the table, the dehumidifying airconditioner of this embodiment can be operated in the cooling operationmode and the dehumidifying operation mode. In the cooling operationmode, all of the desiccant wheel 103, the blower 102, the blower 140,the blower 160, the water spray 325, and the compressor 260 are inoperation or functioning. The flows of the cooling fluid and therefrigerant are the same as those already described.

In the dehumidifying operation mode, while the desiccant wheel 103, theblower 102, the blower 140, and the compressor 260 are in operation, theblower 160 is stopped and the water spray 325 is inoperative. In thatcase, in FIG. 5, the outside air C as the cooling fluid is not flowingand water is not sprayed in the second compartment 320. Therefore, therefrigerant is not deprived of its heat between the throttles 230 and240. Although the refrigerant might be heated (or cooled) transientlywith the process air flowing through the first compartment 310, in theend the evaporation temperature of the refrigerant becomes the samelevel as the process air temperature between the throttles 230 and 240,and they balance each other at the same level, and there is no in- oroutflow of heat. Therefore, when the humid air chart of FIG. 14 isconsidered, cooling is nonexistent between the states L and M. Since theprocess air, after being dehumidified with the desiccant wheel 103, isonly cooled with the refrigerant evaporator 210, the state of theprocess air when it is returned to the conditioning space is low inabsolute humidity and the dry bulb temperature is almost the same as thestate K. That is, this operation mode is basically the dehumidifyingmode. Incidentally, in the embodiment of FIG. 7, the same dehumidifyingoperation mode as that described above is possible if the cooling waterpump 460 is stopped.

As described above, since the heat pump or the dehumidifier of thisinvention is configured such that it includes the process air cooler,that the process air cooler cools the process air by the evaporation ofthe refrigerant, and that the evaporated refrigerant is cooled andcondensed with the cooling fluid, it is possible to utilize evaporatingheat transfer and condensing heat transfer both having high heattransfer coefficients and to carry out heat transfer between the processair and the cooling fluid with a high rate of heat transfer. Since theheat transfer between the process air and the cooling fluid is effectedthrough the refrigerant, component layout of the dehumidifying airconditioner is facilitated.

When the heat pump is configured to include the refrigerant evaporator,the compressor, and the condenser, and is further configured to supplythe refrigerant condensed with the condenser to the process air cooler,the same refrigerant used in the process air cooler can also be used inthe heat pump, and as a result, it is possible to enhance the efficiencyof the dehumidifying air conditioner remarkably.

FIG. 18 is a flow chart of an air conditioning system including adehumidifying air conditioner or desiccant air conditioner as anembodiment of the invention. The dehumidifying air conditioner of thisembodiment has a high COP, constituted as a compact package, and itsoperation mode can be switched to either the cooling operation orheating operation. The heat exchanger shown in FIG. 1 is suitable foruse as the third refrigerant heat exchanger 300 of this invention usedin the air conditioning system of FIG. 18. Also, the refrigerant Mollierchart of the heat pump HP5 included in the air conditioning system ofFIG. 18 is the same as that shown in FIG. 6, and the humid air chartwhen the air conditioning system of FIG. 18 is operated in the coolingmode operation is the same as that explained Referring to FIG. 14.

Referring to FIG. 18, the configuration of the dehumidifying airconditioner as an embodiment of the invention will be described. Thisair conditioning system is to maintain an air conditioning space 101 towhich the process air is supplied as a comfortable environment mainly byreducing the humidity of the process air with a desiccant (dryingagent). As shown, it is configured by arranging devices along the pathof the process air A from the air conditioning space 101 in the orderof; the blower 102 for circulating the process air, the desiccant wheel103 filled with the desiccant, the third refrigerant heat exchanger 300of this invention (when seen from the process air, a cooler in thecooling operation mode, not used as a heat exchanger in the heatingoperation mode), and the first refrigerant heat exchanger 210 (when seenfrom the process air, a cooler in the cooling operation mode, and aheater in the heating operation mode), and that the process air isreturned to the air conditioning space 101.

Also, it is configured by arranging devices along the path of theregeneration air B from outdoors OA in the order of; the passage 124,the sensible heat exchanger 121 which is the heat exchanger forexchanging heat between the air before entering the desiccant wheel 103and the air after exiting the desiccant wheel 103, the passage 126, thesecond refrigerant-air heat exchanger 220 (when seen from theregeneration air B side, a heater in both cooling operation mode anddefrosting operation mode, and a cooler in heating operation mode), thepassage 127, the desiccant wheel 103, the passage 128, the blower 140for circulating the regeneration air, a switching mechanism 145, and theheat exchanger 121, and that the regeneration air B is discharged EXoutdoors. The three-way valve 145 serving as a switching mechanism or abypass value is disposed in the regeneration air passage 129 between theheat exchanger 121 and the discharge port of the blower 140 so that theregeneration air is made to bypass the heat exchanger 121 and dischargeddirectly.

Along the path of the outside air taken from outdoors OA as the coolingfluid C, the third refrigerant-air heat exchanger 300, and the blower160 for circulating the cooling fluid are disposed in that order todischarge EX the outside air outdoors.

Next, the path of the refrigerant will be described. In FIG. 18, therefrigerant flow is set to the cooling operation mode. First, along thepath of the refrigerant, a first refrigerant passage 207 connected tothe second refrigerant intake/discharge port 210 b (serving as arefrigerant outlet in cooling operation mode) of the firstrefrigerant-air heat exchanger 210 (serving as a refrigerant evaporatorin cooling operation mode) is connected to the compressor 260 forcompressing the refrigerant that has evaporated in the firstrefrigerant-air heat exchanger. The refrigerant compressor 260 isconnected through the refrigerant passage 201 to the third refrigerantintake/outlet port 220 a (serving as a refrigerant inlet in coolingoperation mode) provided on the second refrigerant-air heat exchanger220 (serving as a refrigerant condenser in cooling operation mode). Thefourth refrigerant intake/outlet port 220 b (serving as a refrigerantoutlet in cooling operation mode) provided on the second refrigerant-airheat exchanger is connected to the fifth refrigerant intake/outlet port230 a (serving as a refrigerant inlet in cooling operation mode)provided on the third refrigerant-air heat exchanger 300 (serving as aprocess air cooler in cooling operation mode) through the refrigerantpassage 202. A throttle 230 is disposed adjacent to the fifthrefrigerant port 230 a or in the refrigerant passage 202. A sixthrefrigerant intake/outlet port 241 b (serving as a refrigerant outlet incooling operation mode) provided on the third refrigerant-air heatexchanger 300 is connected to the first refrigerant intake/outlet port210 a (serving as a refrigerant inlet in cooling mode) of the firstrefrigerant-air heat exchanger through refrigerant passages 204, 203,and 206. An expansion valve 270 is disposed between the refrigerantpassages 203 and 204.

The refrigerant compressor 260 has a refrigerant intake port 260 a and arefrigerant discharge port 260 b. A four-way valve 265 as a firstswitching mechanism is provided so that the refrigerant passage 207connected to the second refrigerant intake/outlet port 210 b can beselectively connected to either the refrigerant intake port 260 a or therefrigerant discharge port 260 b, and that the refrigerant passage 201can be connected to either the refrigerant intake port 260 a or therefrigerant discharge port 260 b whichever is not connected to therefrigerant passage 207. To describe it further, it is constituted thattwo settings can be selected: In one setting, a refrigerant passage 262is connected to the refrigerant intake port 260 a, a refrigerant passage261 is connected to the refrigerant discharge port 260 b, the four-wayvalve 265 effects intercommunication between the refrigerant passages207 and 262, and the refrigerant passages 261 and 201 areintercommunicated (cooling operation mode, dehumidifying operation mode,and defrosting operation mode). In the other setting, the refrigerantpassages 207 and 261 are intercommunicated and the refrigerant passages262 and 201 are intercommunicated (heating operation mode) (Refer to thetable of FIG. 21).

The embodiment of FIG. 18 is configured such that; a four-way valve 280as the second switching mechanism is disposed adjacent to the thirdrefrigerant-air heat exchanger 300, the refrigerant passage 202 can beselectively connected to one of the fifth refrigerant intake/dischargeport 230 a and the sixth refrigerant intake/discharge port 241 b of thethird refrigerant-air heat exchanger 300, and the refrigerant passage206 can be connected to either the fifth refrigerant intake/dischargeport 230 a or the sixth refrigerant intake/discharge port 241 bwhichever is not connected to the refrigerant passage 202. To describeit further, it is constituted that two settings can be selected: In onesetting, the refrigerant passage 205 is connected to the fifthrefrigerant port 230 a, the refrigerant passage 204 is connected to thesixth refrigerant intake/discharge port 241 b, the refrigerant passage203 is connected through the expansion valve 270 to the sixthrefrigerant port 241 b, the four-way valve 280 effectsintercommunication between the refrigerant passages 202, 205 and betweenthe refrigerant passages 204, 203 and 206 (cooling operation mode anddehumidifying operation mode). In the other setting, the refrigerantpassages 202, 203 are intercommunicated and the refrigerant passages205, 206 are intercommunicated (heating operation mode and defrostingoperation mode) (Refer to the table of FIG. 21).

Here, the connecting relation of the three-way valve 145 as a bypassvalve will be described. The air inlet side of the three-way valve 145is connected to an air passage 129, and one of two branching outlets isconnected to an air passage 130A, so as to lead air to the heatexchanger 121. The other of the two outlets is connected to an airpassage 130B, so that the air bypasses the heat exchanger 121 and isdischarged. The air passage 129 is configured to be selectively switchedbetween a setting in which it communicates with the air passage 130A(cooling operation mode and dehumidifying mode) and a setting in whichit communicates with the air passage 130B (heating operation mode anddefrosting mode) (Refer to the table of FIG. 21).

Now, referring to FIG. 18, refrigerant flow between devices will bedescribed.

First, a cooling operation mode in which a first switching mechanism orfour-way valve 265, a second switching mechanism or four-way valve 280,and a third switching mechanism or three-way valve are set will bedescribed. In FIG. 18, refrigerant gas compressed by the refrigerantcompressor 260 is introduced into the second refrigerant-air heatexchanger (regeneration air heater and refrigerant condenser) 220through a refrigerant gas pipe 261, four-way valve 265, and refrigerantgas pipe 201 connected to the discharge port of the compressor. Thetemperature of refrigerant gas compressed by the compressor 260 has beenraised by compression heat, and the gas heats the refrigerant air in thesecond refrigerant-air heat exchanger 220. Heat is taken from therefrigerant gas itself which then condenses.

Refrigerant liquid exiting a refrigerant outlet 220 b of the secondrefrigerant-air heat exchanger 220 is introduced to an inlet of anevaporating section 251 of a third refrigerant-air heat exchanger 300through a refrigerant path 202, the second switching mechanism 280, anda refrigerant path 205. In the middle of the refrigerant path 205, inthe vicinity of the inlet of the evaporating section 251 is disposed aheader, in which is provided a throttle 230. The throttle 230 may bedisposed in the middle of the refrigerant path 205 in addition to theheader.

Refrigerant liquid exiting the second refrigerant-air heat exchanger 220is reduced in pressure at the throttle 230 to expand, and part of theliquid refrigerant is evaporated (flushed). The refrigerant, that is,the mixture of the liquid and the gas, reaches the evaporating section251, where the liquid refrigerant flows while wetting the inner walls ofthe tubes in the evaporating section, and evaporates to cool the processair flowing in the first compartment.

The evaporating section 251 and a condensing section 252 are of anintegral tube. That is, they constitute an integrated fluid passage, andtherefore, the evaporated refrigerant gas (and unevaporated refrigerantliquid as well) flows into the condensing section 252, then loses theirown heat by the sprayed water and the outside air (ambient air) in thesecond compartment to condense.

At the outlet side of the condensing section 252 is provided a header241. A refrigerant outlet 241 b is connected to a first refrigerant-airheat exchanger 210 through a refrigerant liquid pipe 204, an expansionvalve 270, a refrigerant path 203, the four-way valve 280, and arefrigerant path 206. A fixed throttle may be provided in place of theexpansion valve 270.

In that case, the throttle may be provided in, for example, the header241, or either of the refrigerant paths 204, 203. That is, the throttleor the expansion valve 270 may be, when considering cooling mode only,located at any position immediately behind the condensing section 252 tothe inlet of the second refrigerant-air heat exchanger 210, but in thisembodiment considering also other operation modes and, it is locatedimmediately behind the condensing section 252 and the four-way valve280. However, if it is disposed at a place as close to the inlet 210 aof the first refrigerant-air heat exchanger 210 as possible, thermalinsulation on the piping after the throttle or the expansion valve 270can be minimized for refrigerants significantly colder than theatmospheric temperature. Refrigerant liquid condensed in the condensingsection 252 is lowered in pressure and expanded with the throttle or theexpansion valve 270 to decrease in temperature, flows into the firstrefrigerant-air heat exchanger 210 to be evaporated, and cools theprocess air by the evaporating heat. Throttles 230, 270 disposed beforeand after the third refrigerant-air heat exchanger 300 may be, forexample, orifices, capillary tubes or expansion valves.

In the embodiment of FIG. 18, a throttle provided after the thirdrefrigerant-air heat exchanger 300 is the expansion valve 270 with twoheat sensors. In the cooling operation mode shown in FIG. 18, a heatsensor 275A is activated as a sensor, which is disposed in therefrigerant path between the first refrigerant-air heat exchanger 210and the refrigerant compressor 260. The activated sensor is shown in thefigure in the white block and the deactivated sensor in the shaded one.Then sensor 275A detects the degree of superheating of the refrigerantgas flowing out from the first refrigerant-air heat exchanger 210 usedas a refrigerant evaporator in the cooling operation mode, and theopening of the expansion valve 270 is adjusted so that the refrigerantgas turns into dry gas.

Refrigerant, which is evaporated to be gasified in the firstrefrigerant-air heat exchanger 210, is then introduced into a suctionport 260 a of the refrigerant compressor 260 through a refrigerant path207, the first switching mechanism 265 and a refrigerant path 262, andthe foregoing cycle is repeated.

As the functions of the heat pump HP5 in the cooling operation mode isthe same as described with reference to FIG. 6, explanation is notrepeated.

Referring to FIG. 18 again, a case of dehumidifying operation mode willbe described. In the dehumidifying operation mode, connecting relationsamong the first, second, and third switching mechanisms 265, 280, 145are the same as that in the cooling operation mode. While a desiccantwheel 103, blower 102, blower 140, and compressor 260 are operated, ablower 160 is stopped and a water spray 325 is not activated. At thistime, in FIG. 18, no outside air C as a cooling fluid flows and no wateris sprayed to the second compartment 320, so that no heat is lost fromrefrigerant between the throttle 230 and the expansion valve 270. Thoughthe refrigerant may be transitionally heated (or cooled) by the processair flowing in the first compartment 310, and the evaporationtemperature of refrigerant between the throttle 230 and the expansionvalve 270 will eventually become levelled with that of the process airtemperature, be in balance without any bi-directional heat transfer.Therefore, when considering from the moist air chart in FIG. 14, nocooling occurs between the state L and the state M, and the process airis simply cooled by the first refrigerant-air heat exchanger 210 afterbeing dehumidified by the desiccant wheel 103, and the process airreturned to the air conditioning space is therefore lower in absolutehumidity compared with the state K, and the dry-bulb temperature is in astate not significantly different from the state K. That is, thisoperation mode is basically a dehumidifying operation mode.

Now, referring to FIG. 19, a heating operation mode will be described.In the heating operation mode, the first switching mechanism 265, thesecond switching mechanism 280 and the third switching mechanism 145 arein a connecting relation shown in FIG. 19, as described above. While theblower 102, blower 140 and compressor 260 are operated, the desiccantwheel 103 and blower 160 are stopped, and the water spray 325 is notactivated. Regarding the sensor of the expansion valve 270, a sensor275B disposed in the refrigerant path between the second refrigerant-airheat exchanger 220 and the refrigerant compressor 260 is active.

In FIG. 19, refrigerant discharged from a discharge port 260 b of therefrigerant compressor 260 is sent to the second refrigerant port 210 bthrough the refrigerant path 261, four-way valve 265, and refrigerantpath 207, and releases heat into the first refrigerant-air heatexchanger 210 (acting as a refrigerant condenser in the heatingoperation mode), to be condensed. This obtained heat, heats the processair in a heat exchanging relation with refrigerant in the firstrefrigerant-air heat exchanger 210.

Refrigerant condensed in the first refrigerant-air heat exchanger 210 issent to the third refrigerant-air heat exchanger 300 through therefrigerant path 206, four-way valve 280, and refrigerant path 205.Since the blower 160 is not operated in the heating operation mode,refrigerant passes through the third refrigerant-air heat exchanger 300without exchanging heat with other fluid, and is sent to the secondrefrigerant-air heat exchanger 220 (acting as a refrigerant evaporatorin the heating operation mode) through the refrigerant path 204,expansion valve 270, refrigerant path 203, four-way valve 280, andrefrigerant path 202. In the second refrigerant-air heat exchanger 220,it absorbs heat and is then evaporated. This heat is obtained from theoutside air used for regeneration air during the cooling mode. To thecontrary, the outside air in a heat exchanging relation with therefrigerant is cooled by the evaporating refrigerant.

The refrigerant evaporated in the second air heat exchanger 220 reachesa suction port 260 a though the refrigerant path 201, four-way valve265, and refrigerant path 262, and then compressed in the refrigerantcompressor 260. The refrigerant cycle is repeated in this way. Thedegree of superheating of the refrigerant at the outlet of the secondrefrigerant-air heat exchanger 220 is detected by the sensor 275B of theexpansion valve 270, and the opening of the expansion valve 270 isadjusted so that this refrigerant gas is in a dry state.

The flow of process air A in the heating operation mode is the same asin the cooling operation, but the desiccant wheel 103 is stopped and nodehumidifying operation is performed. Process air passing through thedesiccant wheel is heated by refrigerant in the first refrigerant-airheat exchanger 210, resulting in the increase of dry-bulb temperature,and then supplied, as the air having with adequate dry-bulb temperature,to the air conditioning space 101. A humidifier (not shown) may bedisposed between the heat exchanger 210 and the air conditioning space101.

The flow of outside air B during the heating operation is the same as inthe cooling operation, except that it bypasses the heat exchanger 121.Since no heat exchanging is performed in the heat exchanger 121, theoutside air passes through the heat exchanger to reach the secondrefrigerant-air heat exchanger 220 where it is cooled by evaporatingrefrigerant, and reaches the desiccant wheel 103. Since the desiccantwheel 103 is stopped, it passes through there without exchanging waterand is discharged through the blower 130. The third switching mechanism145 may not be disposed in part 129, but may be disposed between thepath 124 and the path 126 so as to bypass the heat exchanger 121.

Next, referring to FIG. 20, a defrosting operation mode will bedescribed. In the defrosting operation mode, the first switchingmechanism 265, the second switching mechanism 280 and the thirdswitching mechanism 145 are in a connecting relation shown in FIG. 20,as described above. While the blower 160 and the compressor 260 areoperated, the desiccant wheel 103, blower 160 and blower 140 are usuallystopped, and the water sprays 325 are not activated. The sensor 275A isactive as a sensor of the expansion valve 290. The blowers 102 and 140may be operated.

In FIG. 20, refrigerant discharged from the discharge port 260 b of therefrigerant compressor 260 is sent to the third refrigerant port 220 athrough the refrigerant path 261, four-way valve 265, and refrigerantpath 201, and releases heat into the second refrigerant-air heatexchanger 220 to be condensed. This obtained heat, melts or sublimatesand defrosts the frost deposited on the heat transfer surface on the airside of the second refrigerant-air heat exchanger 220. The refrigerantcondensed in the second refrigerant-air heat exchanger 220 is sent tothe third refrigerant-air heat exchanger 300 through the refrigerantpath 202, four-way valve 280, refrigerant path 203, expansion valve 270,and refrigerant path 204. In the defrosting operation mode, since theblower 160 is operated and no water is sprayed, the refrigerant obtainsheat by exchanging heat with outside air C, and then evaporates. Theevaporated refrigerant is sent to the first refrigerant-air heatexchanger 210 through the refrigerant path 205, four-way valve 280, andrefrigerant path 206. In the defrosting operation mode, since the blower102 is stopped, it passes through the first refrigerant-air heatexchanger 210 without exchanging heat, returns to the refrigerantcompressor 260 through the refrigerant path 207, four-way valve 265, andrefrigerant path 262, and the foregoing refrigerant cycle is repeated.The degree of superheating of the refrigerant at the outlet of the thirdrefrigerant-air heat exchanger 300 is detected by the sensor 275A of theexpansion valve 270, and the opening of the expansion valve 270 isadjusted so that this refrigerant gas is in a dry state. In thedefrosting operation as described above, the heat pump HP5 can draw heatfrom outside air C to remove the frost from the second refrigerant-airheat exchanger 220. Thus, a large amount of heat can be drawn for ashort time for defrosting, and defrosting time can be reduced.

Further, in the defrosting operation mode, since the blower 102 is notoperated, no process air A is circulating, and since the blower 140 isnot operated, no regeneration air B is circulating. Therefore, in thisembodiment, no process air is cooled in the defrosting operation mode,so that a high heating effect can be maintained without an uncomfortablefeeling, being created in the air conditioning space 101.

Operation of the different devices has been described in differentoperation modes, and now the operating modes of the dehumidifying airconditioner of an embodiment of this invention and operation of thedevices are summarized in a table of FIG. 21. As shown in the table, thedehumidifying air conditioner of this embodiment is adapted to operatein a cooling operation mode, dehumidifying operation mode, heatingoperation mode and defrosting operation mode. The state of operation andstoppage of the main devices, connection of the switching mechanisms,and sensors used in the expansion valves are as described hereinbefore.

According to this invention as described above, the humidifying airconditioner comprises a third refrigerant-air heat exchanger, and iscapable of switching the selective, connecting relation of the suctionport and discharge port of the refrigerant compressor to the second andthird refrigerant ports, as well as the selective, connecting relationof the fifth and sixth refrigerant ports to the fourth and firstrefrigerant ports, therefore it is possible to provide a dehumidifyingair conditioner capable of cooling operation, heating operation, as wellas defrosting operation, and having an increased COP and compact size.

FIG. 22 shows a flow chart of the dehumidifying air conditioner of anembodiment of this invention, that is, an air conditioning system with adesiccant air conditioner. The dehumidifying air conditioner in thisembodiment is capable of raising the regeneration temperature, inaddition to its increased COP and compact size. For the process aircooler of this invention used with this air conditioning system, theheat exchanger as described with reference to FIG. 9 is suited. FIG. 23is a humid air chart of the dehumidifying air conditioner shown in FIG.22. FIG. 24 is a refrigerant Mollier chart of the heat pump HP6incorporated in the air conditioning system of FIG. 22, and FIG. 25 is achart showing the enthalpy and temperature change of refrigerant andregeneration air in the heat exchangers 220B, 220A incorporated in thisembodiment.

Referring to FIG. 22, the constitution will be described of thedehumidifying air conditioner of an embodiment of this invention. Theair conditioning system is characterized in that the process airtemperature is lowered by desiccant (drying agent), and the airconditioning space 101 supplied with process air is maintained in acomfortable environment. In the figure, the structure of the devicesalong the path of process air from the air conditioning space 101through the desiccant wheel 103 back to the air conditioning space 101is the same as that of the system described in FIG. 8.

It is arranged such that outside air is first introduced, as coolingfluid, from outside OA into the process air cooler 300 c along the pathof regeneration air B, passes through, as regeneration air, therefrigerant condenser (as a heater viewed from regeneration air) 220B,refrigerant sensible heat heat-exchanger 220A, desiccant wheel 103, andblower 140 for providing regeneration air circulation, in this order,and discharged to the outside EX. The refrigerant sensible heatheat-exchanger 220A is also referred to as a first high heat sourceheat-exchanger, and the refrigerant condenser 220B as a second high heatsource exchanger.

Further, it is configured such that the devices along the path ofrefrigerant beginning at refrigerant evaporator 210 are arranged in thefollowing order: a refrigerant heat exchanger 270 for exchanging heatbetween cold refrigerant gas evaporated in the refrigerant evaporator210 to be gasified and hot refrigerant introduced from the refrigerantsensible heat heat-exchanger 220A; a compressor 260 for compressingrefrigerant gas passing through the refrigerant heat exchanger 270 to beheated by exchanging heat with hot refrigerant from the refrigerantsensible heat heat-exchanger 220A; a refrigerant sensible heatheat-exchanger 220A for absorbing mainly the sensible heat ofrefrigerant delivered after being compressed by the compressor 260 toturn the refrigerant into saturated refrigerant vapor; a refrigerantheat exchanger 270 for exchanging heat between the refrigerant gas fromthe refrigerant sensible heat heat-exchanger 220A and the refrigerantgas from the refrigerant evaporator 210 as described above; arefrigerant condenser 220B for absorbing mainly latent heat ofrefrigerant to condense the refrigerant; a header 235; a plurality ofthrottles 230A, 230B, 230C branched off from the header and disposed inparallel; a process air cooler 300 c; a plurality of throttles 240A,240B, 240C corresponding to the throttles 230A, 230B, 230C; and a header245 for collecting flows from these throttles, and thus the refrigerantgas returns to the refrigerant evaporator 210 again. An expansion valve250 may be provided between the header 245 and the refrigerantevaporator 210, as shown in the figure. In this way, the heat pump HP6is configured, including the refrigerant evaporator 210; compressor 260;refrigerant sensible heat heat-exchanger 220A; refrigerant condenser220B; plurality of throttles 230A, 230B, 230C; process air cooler 300;plurality of throttles 240A, 240B, 240C.

The heat exchanger 300 c as a process air cooler incorporated in thisembodiment is described with reference to FIG. 9.

Functions of the embodiment of this invention will be described withreference to the humid air chart in FIG. 23, and for the structure, toFIG. 22 as appropriate. In FIG. 23, alphabetical symbols K-N, Q, R, X,T, and U denote the states of air in respective sections. Those symbolscorrespond to the encircled letters in the flow chart of FIG. 22.

First, the flow of process air A will be described. In FIG. 23, processair (in the state K) from the air conditioned space 101 is drawn by theblower 102 through the process air path 107, and sent through theprocess air path 108 into the desiccant wheel 103, where it is adsorbedof its moisture by desiccant in the drying elements 103 a (FIG. 16) to,lower absolute humidity, and raise the dry-bulb temperature using theadsorption heat of the desiccant, and then reaches the state L. This airis sent through the process air path 109 to the first compartment 310 ofthe process air cooler 300, where it is cooled by evaporated refrigerantwith absolute humidity kept constant in the evaporating section 251(FIG. 9), to be turned into air in the state M, and enters the cooler210 through the path 110. There, it is further cooled, with absolutehumidity kept constant, to be turned into air in the state N. This airis returned to the air conditioning space 101 via the duct 111, asprocess air SA with an adequate humidity and at an adequate temperature.

Next, the flow of regeneration air B will be described. In FIG. 23,regeneration air (the state Q) from the outside OA is drawn through theregeneration air path 124 and sent to the second compartment 320 of theprocess air cooler 300, where it exchanges heat with condensingrefrigerant (exchanges heat indirectly with process air), raises thedry-bulb temperature, and turns into air in the state R. This air issent through the path 126 into the refrigerant condenser (as a heaterviewed from regeneration air) 220B, where it is heated to raise thedry-bulb temperature, then turns into air in the state S, further entersthe sensible heat heat-exchanger 220A, and is heated further to turninto air in the state T. This air is sent through the path 127 into thedesiccant wheel 103, by which moisture is removed from the desiccant inthe drying elements 103 a (FIG. 16) for regeneration, then raises itsown absolute humidity and lowers dry-bulb temperature by moistureremoval heat, and enters the state U. This air is drawn through the path128 into the blower 140 for providing regeneration air circulation, anddischarged EX through the path 129.

In the air conditioner as described above, the relation of heat quantityΔH applied to regeneration air, heat quantity Δq drawn from process air,and drive energy Δh of the compressor is the same as described in FIG.14. In this embodiment, heat exchange efficiency of the process aircooler 300 c is very high, thereby remarkably improving cooling effect.

Next, referring to the flow chart in FIG. 22 and the Mollier chart inFIG. 24, the flow of refrigerant between devices, and functions of theheat pump HP6 will be described.

In FIG. 22, refrigerant compressed by the refrigerant compressor 260 isintroduced into the sensible heat heat-exchanger 220A through therefrigerant gas pipe 201 connected to the discharge port of thecompressor. The refrigerant gas compressed by the compressor 260 israised in temperature by compression heat, and the regeneration air isheated by this heat. In this state, refrigerant is deprived mainly ofits sensible heat. As a result, the refrigerant is approximately in thestate of saturation, but actually, in the state of superheat which mayturn into the state of saturation if the refrigerant is deprived of onlya small amount of heat, or in the wetting state, that is, in the perfectsaturated gas (or the perfect saturated gas mixed with liquid condensedfrom part of refrigerant. The state in the vicinity of the saturated gasis referred to as a state of approximate saturation. The refrigerant inthe state of approximate saturation is introduced through therefrigerant pipe 225 into the refrigerant heat exchanger 270, where itexchanges heat with cold refrigerant gas before taken into thecompressor 260, then evaporates in the refrigerant evaporator 210, turnsin part into the wetting state, and is introduced through therefrigerant path 206A into the refrigerant condenser as a (heater viewedfrom regeneration air) 220B, where it is deprived of its heat to becondensed.

The refrigerant outlet of the refrigerant condenser 220B is connectedvia the refrigerant path 202 to the header 235 provided at the inlet ofthe evaporating section 251 of the heat exchanger or the process aircooler 300 c. Between the header 235 and the evaporating section 251,throttles 230A, 230B, 230C are provided corresponding to the evaporatingsections 250A, 250B, 251C, respectively. While only three throttles areshown in FIG. 22, any number of throttles more than one may be arrangeddepending on the number of the evaporating sections 251 or thecondensing sections 252.

Liquid refrigerant exiting the refrigerant condenser (as a heater viewedfrom regeneration air) 220B is lowered in pressure at the throttles230A, 230B, 230C and then expanded, and part of the liquid refrigerantis evaporated (flushed). Refrigerant which is the mixture of the liquidand gas, reaches the evaporating sections 251A, 251B, 251C, where theliquid refrigerant flows in the tubes of the evaporating sections whilewetting the inner wall of the tubes is evaporated, and cools the processair flowing in the first compartment.

As described above, the evaporating sections 251A, 251B, 251C and thecondensing section 252A, 252B, 252C are formed with a series of tubes,respectively, constituting an integral path, respectively.

The heat exchanger 300 c for heat pump shown in FIG. 22 is the same asdescribed with reference to FIG. 8, in that throttles are interposedbetween the header 235 and the evaporating section, that the throttlesare allocated separately to a plurality of evaporating sections, andthat throttles are allocated separately to the corresponding condensingsections between them and the header, respectively.

In the constitution, as described with reference to FIG. 8, the processair cooler 300 c is configured such that there exists a plurality ofevaporating pressures of refrigerant which cools process air A, and aplurality of condensing pressures of refrigerant which is cooled byoutside air B and condensed, corresponding to the foregoing evaporatingpressures, and the plurality of the evaporating pressures or thecondensing pressures are arranged from high to low or from low to highin order of their pressure level. In this way, noting the flow ofprocess air A and that of outside air B, they exchange heat, so tospeak, in counter flow relation, so that a remarkably high heat exchangeefficiency φ, for example over 80%, can be realized.

Here, throttles 230A, 230B, 230C and throttles 240A, 240B, 240C areprovided before and after the process air cooler 300 c, respectively.Alternatively, throttles may be provided immediately before the header235 or in the header 235, or after the header 245 or in the header 245,one for each place, thereby simplifying the plurality of pressures ofevaporating sections or condensing sections into one value. In thiscase, the process air and the regeneration air are not necessarily incounter flow relation, but evaporating heat transfer and condensing heattransfer can be utilized, so that high heat transfer coefficient can belikewise applied to the heat transfer between process air andregeneration air.

As described above with reference to FIG. 9, the evaporating section andcondensing section are constituted integrally by a series ofheat-exchange tubes, but they may be replaced with a heat exchangerhaving a first and a second compartment separated as shown in FIG. 3.

This header 245 on the condensing section 252 side is connected by therefrigerant liquid pipe 203 to the refrigerant evaporator 210 (as acooler viewed from process air). Throttles 240A, 240B, 240C may bedisposed anywhere from a place immediately after the condensing sections252A, 252B, 252C to the inlet of the refrigerant evaporator. 210, but ifthey are disposed immediately before the inlet of the refrigerantevaporator 210, thermal insulation of pipes can be thinner for therefrigerant after the throttles 240A, B, C at a temperaturesignificantly lower than the atmospheric temperature. The refrigerantcondensed in the condensing sections 252A, B, C is lowered in pressureand expanded to decrease in temperature, then enters the refrigerantevaporator 210 to be evaporated, and cools the process air by theevaporating heat. Throttles 230A, B, C or 240A, B, C may be orifices,capillary tubes or expansion valves, etc.

Next, referring to FIG. 24, functions of the heat pump HP6 will bedescribed. FIG. 24 is a Mollier chart of the system using HFC 134 a asrefrigerant. In this chart, the horizontal axis represents the enthalpyand the vertical axis the pressure.

In the figure, the point q represents the state at refrigerant outlet ofthe refrigerant evaporator 210 shown in FIG. 22, and it is in the stateof q saturated gas. The pressure is 4.2 kg/cm², the temperature 10° C.,and the enthalpy 148.83 kcal/kg. A state in which this gas is heated inthe refrigerant heat exchanger 270 is shown by the point a. The pressureof this state is 4.2 kg/cm² (actually lowered by the amount of pressureloss in the refrigerant pipes and the heat exchanger, which is neglectedhere. The same is applied to the following description), and thetemperature 55° C. The refrigerant gas in this state is drawn into thecompressor 260 to be compressed and reaches the state b at the dischargeport of the compressor 260. In the state of the point b, the pressure is19.3 kg/cm² and the temperature 115° C. If no heat exchanger is providedin the inlet path of the compressor, this temperature should be 80° C.or so, but in this embodiment, it shows 115° C. This is becauserefrigerant has been heated in the refrigerant heat exchanger 270.

This refrigerant gas is deprived mainly of sensible heat in the sensibleheat heat-exchanger 220A and reaches the point c. This point representsthe state of approximately saturated gas; the pressure is 19.3 kg/cm²and the temperature 65° C. The gas exchanges heat with cold refrigerantbefore intake to the compressor 260, deprived of its heat, and reachesthe point p. This point represents the wetting state in whichrefrigerant gas and refrigerant liquid coexist. This refrigerant isfurther deprived of its heat in the refrigerant condenser 220B andreaches the point d. This point represents the state of saturatedliquid; the pressure and temperature are the same as those of the pointc or q, and the pressure is 19.3 kg/cm², the temperature 65° C., and theenthalpy 122.97 kcal/kg.

The state of part of the refrigerant liquid which is lowered in pressureat the throttle 230A and flows in the evaporating section 251A, isrepresented at the point e1 on the Mollier chart. The temperature isapproximately 43° C. The pressure is one of a plurality of differentpressures, a saturated pressure corresponding to the temperature of 43°C. Likewise, the state of refrigerant lowered in pressure at thethrottle 230B and flowing in the evaporating section 251B, isrepresented at the point e2 on the Mollier chart; the temperature is 40°C. and the pressure is also one of a plurality of different pressures, asaturated pressure corresponding to the temperature of 40° C. Likewise,the state of refrigerant lowered in pressure at the throttle 230C andflowing in the evaporating section 251C, is represented at the point e3on the Mollier chart; the temperature is 37° C. and the pressure is alsoone of a plurality of different pressures, a saturated pressurecorresponding to the temperature of 37° C.

At any point of e1, e2, e3, the refrigerant is in a state in which partof the liquid is evaporated (flushed) and the liquid and the gas aremixed together. The refrigerant liquids are each evaporated in therespective evaporating sections 251A, B, C under the pressure of one ofthe foregoing respective plurality of different pressures, and reach thepoints f1, f2, f3, for respective pressures, intermediate between thesaturated liquid line and saturated gas line.

The refrigerants in these states flow in the condensing sections, 252A,252B, 252C. In the condensing sections,the refrigerants are eachdeprived of their heat by outside air flowing the second compartment,and reach the respective points g1, g2, g3. These points are on thesaturated liquid line in the Mollier chart. The temperatures are 43° C.,40° C. and 37° C., respectively. These refrigerant liquids each passthrough the throttles and reach the respective points j1, j2, j3. Thepressures at these points are a saturated pressure of 4.2 kg/cm² at 10°C.

Here, the refrigerants are in a state of mixture of liquid and gas.These refrigerants join at one header 245, therefore the enthalpy atthis point is an average of enthalpies at the points g1, g2, g3 weightedby the corresponding refrigerant flow rates, and amounts toapproximately 113.51 kcal/kg in this example.

This refrigerant deprives process air of its heat in the refrigerantevaporator 210, evaporates into q saturated gas in the state of thepoint q on the Mollier chart, and flows again in the refrigerant heatexchanger 270. In this way, the above described cycle is repeated.

Functions of the heat exchanger 300 c is the same as described withreference to FIG. 9. That is, process air is cooled from a highertemperature to a lower temperature as it flows from the upper side tothe lower side on the figure in the first compartment 310, attemperatures 43° C., 40° C. and 37° C. in order of temperature level, sothat heat exchange efficiency can be improved compared with thatobtained when process air is cooled at one temperature of, for example,40° C. Also, outside air (regeneration air) is heated from a lowertemperature to a higher temperature as it flows from the lower side tothe upper side on the figure in the second compartment 320, attemperatures 37° C., 40° C. and 43° C. in order of temperature level, sothat heat exchange efficiency can be improved compared with thatobtained when process air is heated at one temperature of, for example,40° C.

Further, if the heat exchanger 300 c is provided, the compression heatpump HP6 including the compressor 260, refrigerant condenser 220B,throttles and refrigerant evaporator 210, is able to reduce the requiredpower of the compressor by 27%, as described with reference to FIG. 10.Oppositely saying, the cooling effect achievable with the same power canbe improved by 37%.

Further, as a result that refrigerant is heated in the refrigerant heatexchanger 220A before it is drawn into the compressor 260, the ratio ofthe heat quantity of regeneration air heated at temperatures above thecondensing temperature of the refrigerant in the sensible heatheat-exchanger 270 to that of regeneration air heated at a constantcondensing temperature in the condenser 220B is 35%:65%. Compared withthe example of FIG. 10 in which the ratio is approximately 12%:88%, thedifference is great.

Referring to FIG. 25, the temperature rise of the regeneration air inthe foregoing dehumidifying air conditioner will be described. FIG. 25is a chart showing the relation of regeneration air vs. changes(variation) in enthalpy of high pressure refrigerant in the heat pumpHP6 used for the heat source of the regeneration air. When refrigerantin the heat pump exchanges heat with regeneration air, changes inenthalpy of refrigerant and regeneration air are the same because ofheat balance. Since air undergoes a sensible heat change with theapproximately constant specific heat, it is shown in the figure by acontinuous straight line, while since refrigerant undergoes latent heatchange and sensible heat change, it is shown by a horizontal line forthe region with latent heat change. Therefore, the temperature ofregeneration air at the outlet of the condenser 220B is determined, theregeneration air temperature at the outlet of the sensible heatheat-exchanger 220A can be calculated based on heat balance, not basedon the temperature of superheated vapor of the refrigerant with whichheat is to be exchanged.

Therefore, in FIG. 25, if the refrigerant cycle is the same as in FIG.24, the regeneration temperature at the inlet of the condenser 220B is40° C., and the refrigerant condensing temperature is 65° C., thetemperature Ts of the state S is Ts=40+(65−40)×80/100=60° C., assumingthe heat exchange efficiency of the condenser 220B of the heat pump tobe 80% in this embodiment. Then, if the regeneration air is heated bythe superheated refrigerant vapor by 35% of the total heat quantity byheating, the temperature Tt of the air in the state T isTt=60+20×35/65=70.8° C., from heat balance as described above.Therefore, regeneration air can be obtained, the temperature of which ishigher than the condensing temperature of 65° C. by 5.8° C.

Therefore, since in this embodiment, desiccant can be regenerated at ahigher temperature than the condensing temperature, the dehumidifyingability of the desiccant can be improved remarkably, thereby providingan air conditioning system with excellent dehumidifying ability as wellas energy saving properties. Regarding regeneration air, discharged airfrom the room in association with room ventilation may be utilized withthe same effects as in foregoing embodiment.

Referring to FIG. 26, the structure of the dehumidifying air conditionerof an embodiment of this invention will be described. The differencefrom the embodiment of FIG. 22 is that while in the example of FIG. 22,refrigerant flowing out from the sensible heat heat-exchanger 220A, isdeprived of sensible heat and in the state of approximate saturation,and all of the refrigerant is introduced into the refrigerant heatexchanger 270, in the embodiment of FIG. 26 the refrigerant path 206connected to the refrigerant heat exchanger 270 is branched off from therefrigerant path 225 from the sensible heat exchanger 220A, and part ofthe refrigerant from the sensible heat heat-exchanger 220A is adapted topass through the refrigerant heat exchanger 270. The refrigerantdeprived of its heat is introduced from the refrigerant heat exchanger270 to the header 235, through the refrigerant path 207, and joins therefrigerant from the condenser 220B. Therefore, while in the embodimentin FIG. 22 the refrigerant from the sensible heat heat-exchanger 220A isdeprived of its heat to the extent that it turns into the wetting statein the refrigerant heat exchanger 270, in the embodiment of FIG. 26, therefrigerant condenses almost completely as a result of the heatdeprivation in the refrigerant heat exchanger 270. In this embodiment,if the appropriate selection is made with respect to the ratio of theamount of refrigerant flowing in the refrigerant heat exchanger 270 tothat of refrigerant flowing in the condenser 220B, the temperature ofthe point b on the Mollier chart in FIG. 24 can be set appropriately.Other general effects and functions are approximately the same as thosein the embodiment of FIG. 22.

Referring new to FIG. 27, the structure will be described of thedehumidifying air conditioner of still another embodiment of theinvention. In this embodiment, like the embodiment of FIG. 26,refrigerant flows out from the sensible heat heat-exchanger 220A and isalmost deprived of sensible heat, and part of the refrigerant isintroduced through the refrigerant path 206 into the refrigerant heatexchanger 270, to be deprived of its heat and condensed, but unlike theembodiment of FIG. 26, the refrigerant from the refrigerant heatexchanger 270 passes through the path 207, throttle 275, and path 208and joins the path 203 between the header 245 and expansion valve 250 orthe evaporator 210.

Therefore, on the Mollier chart in FIG. 24, refrigerant from therefrigerant heat exchanger 270 is throttled at the throttle 275 (and theexpansion valve 250) from the state of the point d and evaporates in theevaporator 210, so that cooling effect is somewhat lower than that inthe foregoing embodiment, though problems in arrangement of the heatexchanger can be eliminated.

Referring to FIG. 28, the structure will be described of thedehumidifying air conditioner of yet another embodiment of theinvention. In this embodiment, the process air cooler can suitablyutilize the heat exchanger 300 described above with reference to FIG. 1.This heat exchanger 300, as described above, utilizes evaporating heattransfer and condensing heat transfer, so that heat transfer coefficientis excellent and thus heat exchange efficiency is very high. Therefrigerant is passed through from the evaporating section 251 towardthe condensing section 252, that is, forced to flow approximately in onedirection, so that heat exchange efficiency is high between process air,and outside air as a cooling fluid.

In this embodiment, the flow of process air is the same as that in otherembodiments, and its description is not repeated. Now, the flow ofregeneration air B will be described. In FIG. 28, regeneration air(state Q) from outside OA is drawn through the regeneration air path 124and sent into the heat exchanger 121, where it exchanges heat withregeneration air (air of the state U described later) which has a raisedtemperature and needs be discharged, raises the dry-bulb temperature,and then turns into air of the state R. This air is sent through thepath 126 into the refrigerant condenser 220B, where it is heated toraise the dry-bulb temperature and then turns into air of state S, andflows into the sensible heat heat-exchanger 220A to be heated and thenturns into air of the state T. This air is sent through the path 127into the desiccant wheel 103, where it deprives, of moisture, thedesiccant in the drying element 103 a (FIG. 16) for regeneration, raisesits own absolute humidity, lowers dry-bulb temperature by moistureremoval heat, and reaches the state U. This air is drawn through thepath 128 into the blower 140 for providing regeneration air circulation,sent through the path 129 into heat exchanger 121, exchanges heat withregeneration air (air of the state Q) before feed-in to the desiccantwheel 103, as described above, lowers its own temperature to turn intothe air of the state V, and is discharged EX through the path 130..

The flow of outside air C as a cooling fluid is the same as described inFIG. 5. That is, in this embodiment, as a result of functions of thehumidifier 165 and spray pipes 325, the temperature of outside air as acooling fluid is lowered, which is useful for improving cooling effect.Also, on the second compartment side of the condensing section 252,cooling effect due to latent heat produced by water evaporation can beexpected.

In the cooling cycle, regarding refrigerant from the sensible heatheat-exchanger 220A, like the embodiment shown in FIG. 27, part of therefrigerant is sent to the refrigerant heat exchanger 270, and therefrigerant condensed in the refrigerant heat exchanger 270 joins,through the throttle 275, to the path 203 between the throttle 240acting also as a header of the condensing section and the expansionvalve 250 or the evaporator 210. On the Mollier chart in FIG. 24,refrigerant passing the throttle 230 is reduced in pressure from thestate of the point d to, for example, the state of the point e2, at thispoint takes heat from process air, and proceeds to the point f2, whereit is deprived of heat further by cooling fluid, and reaches the pointg2. Then, it is reduced in pressure at the throttle 240 and reaches thepoint j2. That is, the evaporating pressure, or the condensing pressurein the process air cooler 300 takes one value, therefore it cannot besaid that heat-exchange between process air and cooling fluidconstitutes a counterflow. However, in the process air cooler 300, likethe foregoing embodiment, it also utilizes evaporating heat transfer andcondensing heat transfer, and further, water is sprayed so as to lowerthe temperature of the refrigerant and removes heat by evaporating heattransfer, thereby producing a high cooling effect as well.

In addition, as a variation of the embodiment of FIG. 28, like theembodiment of FIG. 22, all the refrigerant from the sensible heatheat-exchanger 220A may be inducted into the refrigerant heat exchanger270 and then the condenser 220B. Also, like the embodiment of FIG. 26,part of refrigerant may be passed through the refrigerant heat exchanger270, in which the refrigerant condensed may be then inducted to thethrottle 230 so as to join the refrigerant condensed in the condenser220B.

According to this invention as described above, refrigerant, afterhaving been compressed by the compressor, exchanges heat withregeneration air before regeneration of desiccant, to be turned intoapproximately saturated vapor, and this refrigerant is therefore able toheat refrigerant before intake to the compressor, so that the dischargetemperature of the refrigerant compressed by the compressor is raised,resulting in raising of regeneration air before regeneration ofdesiccant. Further, since the process air cooler is provided, heatexchange between process air and cooling fluid is performed byevaporating and condensing heat transfer with high heat transfercoefficient, thereby providing a dehumidifying air conditioner with highCOP and compact size.

FIG. 29 is a flow chart of an air conditioning system incorporating thedehumidifying air conditioner of an embodiment of this invention, thatis, the desiccant air conditioner; FIG. 30 is a schematic sectional viewof an example of the heat exchanger as a process air cooler of thisinvention suitable to the air conditioning system of FIG. 29; FIG. 31 isa moist air chart of the dehumidifying air conditioner of an embodimentof this invention; FIG. 32 shows refrigerant Mollier charts of the heatpumps HPA, HPB incorporated in the air conditioning system of FIG. 29.The dehumidifying air conditioner of this embodiment has a high COP andcompact size. Among others, temperature lift of the heat pump is low,thereby reducing the amount of power required.

Referring to FIG. 29, the structure will be described of a dehumidifyingair conditioner of an embodiment of this invention. The air conditioningsystem is characterized in that the process air temperature is loweredby desiccant (drying agent), and the air conditioning space 101 suppliedwith the process air is maintained in a comfortable environment. Asshown in the figure, the dehumidifying air conditioner is arranged suchthat from the air conditioning space 101, disposed along the path ofprocess air A are the blower 102 for providing process air circulation;desiccant wheel 103 as a moisture adsorber filled with desiccant;process air cooler 300 e of this invention; first evaporator (as acooler viewed from process air) 210A of this invention; and secondevaporator (as a cooler viewed from process air) 210B of this invention,in this order, and process air A returns to the air conditioning space101 again.

Also, it is arranged such that from outside (OA), disposed along thepath of regeneration air B are, first, the process air cooler 300 e forreceiving outside air as a cooling fluid; then, the second condenser (asa heater viewed from regeneration air) 220B of this invention; the firstcondenser (as a heater viewed from regeneration air) 220A of thisinvention; desiccant wheel 103; and blower 140 for providingregeneration air circulation, in this order, and the outside air whichis the cooling fluid and used for regeneration air, is discharged (EX)to the outside.

Further, it is arranged such that from the refrigerant evaporator 210A,disposed along the path of refrigerant are compressor 260A, as a firstcompressor, for compressing the gasified refrigerant evaporated in therefrigerant evaporator 210A ; refrigerant condenser 220A; throttle 230A;process air cooler 300; throttle 240A corresponding to the throttle230A; and expansion valve 270A, in this order, and the refrigerantreturns to the refrigerant evaporator 210A again. The first heat pumpHPA includes the refrigerant evaporator 210A; compressor 260A;refrigerant condenser 220A; throttle 230A; process air cooler 300 e(evaporating section 251A and condensing section 252A); and throttle240A.

Quite similarly, the second heat pump HPB is provided in parallel withthe first heat pump HPA. That is, it is arranged such that from therefrigerant evaporator 210B, disposed along the path of refrigerant arecompressor 260B, as a second compressor, for compressing the gasifiedrefrigerant evaporated in the refrigerant evaporator 210B; refrigerantcondenser 220B; throttle 230B; process air cooler 300 (evaporatingsection 251B and condensing section 252B); throttle 240B correspondingto the throttle 230B; and expansion valve 270B, in this order, and therefrigerant returns to the refrigerant evaporator 210B again. The heatpump HPB includes the refrigerant evaporator 210B; compressor 260B;refrigerant condenser 220B; throttle 230B; process air cooler 300; andthrottle 240B.

The desiccant wheel 103 used here is as described with reference to FIG.16, and the air paths of process air and regeneration air on theupstream and downstream sides of the desiccant wheel 103 are separatedby an appropriate partition plate (not shown) such that the air in thesetwo systems do not mix to each other.

Next, referring to FIG. 30, the structure will be described of the heatexchanger as a process air cooler preferred for use in the dehumidifyingair conditioner of an embodiment of this invention. In the figure, theheat exchanger 300 e is provided with the first compartment 310 in whichprocess air A flows, and the second compartment 320 in which outside air(utilized as regeneration air) as a cooling fluid flows, adjacent toeach other with a partition wall there between.

A plurality of heat-exchanging tubes (two tubes in this figure) areprovided approximately horizontally, which go through the first andsecond compartment 310, 320 and the partition wall 301, and throughwhich refrigerant 250 flows. One portion of this heat-exchanging tubingpassing through the first compartment, constitutes the evaporatingsection 251 (a plurality of evaporating sections are designated by 251Aand 251B) as a first fluid path, and the another portion passing throughthe second compartment constitutes the condensing section 252 (aplurality of condensing sections are designated by 252A and 252B) as asecond fluid path.

In the embodiment shown in FIG. 30, each of the evaporating sections251A, 251B and the condensing sections 252A, 252B is formed of a singletube and constitutes an integral path. Therefore, the heat exchanger 300can be formed in compact size as a whole, in combination with the firstand second compartments 310, 320 being provided adjacent to each other,with a partition plate 301 disposed therebetween. The evaporatingsection 251A may comprise a plurality (not single section, as shown) ofsections 251A1, 251A2, 251A3 . . . , for one throttle 230A, depending onthe length of the section, cross sectional compartment, or refrigerantflow rate. The condensing section may comprise a plurality of sections252A1, 252A2, 252A3 . . . , accordingly. The plurality of sections maybe disposed in multiple rows in the direction of the flow of process airand regeneration air or in the direction perpendicular to the flow, orboth of the directions as a matter of course.

In the embodiment of FIG. 30, the evaporating sections are arranged inrows of 251A and 251B in this order from the upper side of the figure,and condensing sections, also in rows of 252A and 252B in this orderfrom the upper side of the figure. When the evaporating sections 251Aand the condensing sections 252A are disposed in multiple rows,respectively, in the direction of the flow of process air andregeneration air, the evaporating sections are arranged in rows of251A1, 251A2, 251A3 . . . , in this order from the upper side of thefigure, and the condensing sections, in rows of 252A1, 252A2, 252A3 . ..

On the other hand, in the figure, process air A flows into the firstcompartment at the upper side through the duct 109 and out from thelower side, while outside air B which is a cooling fluid and used forregeneration air, flows into the second compartment at the lower sidethrough the duct 124 and out from the upper side. That is, the processair A and outside air B flow in counterflow manner.

In such a process air cooler or heat exchanger, the evaporating pressureat the evaporating section 251 and thus the condensing pressure at thecondensing section 252A depend on the temperatures of the process air Aand the outside air B as a cooling fluid. The heat exchanger 300 e shownin FIG. 30 utilizes evaporating heat transfer and condensing heattransfer, so that heat transfer coefficient is excellent and thus heatexchange efficiency is very high. Also, the refrigerant is passedthrough from the evaporating section 251A toward the condensing section252A, that is, forced to flow approximately in one direction, so thatheat exchange efficiency is high between process air, and outside air asa cooling fluid. The heat exchange efficiency φ has been described withreference to FIG. 4.

Taking account of the direction of the refrigerant flow, though theevaporating pressure is a little higher than the condensing pressure,they are considered to be substantially the same because the evaporatingsection 251A and the condensing section 252A are configured with anintegral, continuous heat-exchanging tube.

While the evaporating section 251A and the condensing section 252A hasbeen described above, functions are quite the same for the evaporatingsection 251B and the condensing section 252B. However, since the processair flow is directed from the evaporating section 251A toward 251B, andthe cooling fluid flow is directed from the condensing section 252Btoward 252A, evaporating or condensing pressure of the evaporatingsection 251A or the condensing section 252A is higher than that of theevaporating section 251B or the condensing section 252B.

The inner surfaces of the heat-exchanging tubes constituting theevaporating section 251 and the condensing section 252, are preferablyhigh quality heat transfer surfaces already described.

The plate fins on the outer side of the heat-exchanging tube in thefirst compartment or the ones in the second compartment are the same asdescribed with reference to FIG. 1.

Functions of the embodiment of this invention will be described withreference to FIG. 31, and for the structure, to FIG. 29 as appropriate.In FIG. 31, alphabetical symbols K-N, P, Y, Q-U and X designate thestates of air in respective sections. These symbols correspond to theletters encircled in the flow chart of FIG. 29.

First, the flow of process air A will be described. In FIG. 31, processair (in the state K) from the air conditioning space 101 is drawn by theblower 102 through the process air path 107, and sent through theprocess air path 108 into the desiccant wheel 103, where it is adsorbedof its moisture by desiccant in the drying element 103 a (FIG. 16) tolower absolute humidity, raises dry-bulb temperature with adsorptionheat of the desiccant, and reaches the state L. This air is sent throughthe process air path 109 to the first compartment 310 of the process aircooler 300 where it is cooled by refrigerant which evaporates, withabsolute humidity kept constant, in the evaporating section 251A (FIG.30) at the first intermediate temperature or the third pressure of thisinvention, to be turned into air in the state P; further cooled byrefrigerant which evaporates in the evaporating section 251B (FIG. 30)at the second intermediate temperature or the fourth pressure of thisinvention, to be turned into air of the state M; and enters the cooler210A through the path 110. There, it is cooled further, also withconstant absolute humidity, at the first evaporation temperature or thefirst evaporating pressure of this invention, to be turned into air inthe state Y, and subsequently enters the cooler 210B, to be cooledfurther at the second evaporation temperature or the second evaporatingpressure of this invention, to be turned into air of state N. This air,after having been dried and cooled, is returned to the air conditioningspace 101 via the duct 111, as process air SA with an adequate humidityand at an adequate temperature (absolute humidity of 6 kg/kg and 19° C.in FIG. 31).

Next, the flow of regeneration air B will be described. In FIG. 31,regeneration air (the state Q) from the outside (OA) is drawn throughthe regeneration air path 124 and sent to the second compartment 320 ofthe process air cooler 300, where it exchanges heat with refrigerantwhich condenses at a temperature approximately equal to the secondintermediate temperature or a pressure approximately equal to the fourthpressure of this invention in the condensing section 252B, raisesdry-bulb temperature, and then turns into air of the state S, andsubsequently it exchanges heat with refrigerant which condenses at atemperature approximately equal to the first intermediate temperature ora pressure approximately equal to the third pressure of this inventionin the condensing section 252A, raises dry-bulb temperature, and thenturns into air of the state R. This air is sent through the path 126into the refrigerant condenser (heater viewed from regeneration air)220B, where it is heated at the second condensing temperature or thesecond condensing pressure, raises dry-bulb temperature, and then turnsinto air of the state X, and enters the refrigerant condenser 220A,where it is heated at the first condensing temperature or the firstcondensing pressure, raises dry-bulb temperature, and then turns intoair of the state T. This air is sent through the path 127 into thedesiccant wheel 103, where it removes moisture from the desiccant in thedrying element 103 a (FIG. 16) for regeneration, raises its own absolutehumidity, lowers dry-bulb temperature with moisture removal heat, andreaches the state U. This air is drawn through the path 128 into theblower 140 for providing regeneration air circulation, and discharged EXthrough the path 129. In the air conditioner described above, as seenfrom the air cycle shown on the humid air chart in FIG. 31, assumingthat heat quantity applied to the regeneration air for regeneration ofthe desiccant of the conditioner be ΔH, heat quantity pumped up fromprocess air be Δq, and drive energy of the compressor be Δh, thenΔH=Δq+Δh. The cooling effect ΔQ obtained as a result of regeneration bythe heat quantity ΔH, is larger for a lower temperature of outside air(state Q) with which process air (state L) is to exchange heat aftermoisture adsorption. Also, it is larger for a smaller temperaturedifference between the state Q and state M, and between the state R andstate L. In this embodiment, since heat exchange efficiency of theprocess air cooler 300 is very high, cooling effect can be improvedremarkably. The temperature lift to be pumped up by the heat pump is 37°C., the temperature difference between the state T and state Y, for thefirst heat pump HPA, and 35° C., the temperature difference between thestate X and state N, for the second heat pump HPB.

Now, referring to FIG. 29 and FIG. 32, the refrigerant flow betweendevices and functions of heat pumps HPA, HPB will be described.

In FIG. 29, refrigerant gas compressed by the first refrigerantcompressor 260A is introduced through the refrigerant gas pipe 201Aconnected to the discharge port of the compressor into the firstcondenser or the regeneration air heater (refrigerant condenser) 220A.The refrigerant gas compressed in the compressor 260A is raised intemperature by compression heat and regeneration air is heated by thisheat. The refrigerant gas is deprived of its own heat to be cooled, andis condensed further.

The refrigerant outlet of the refrigerant condenser 220A is connected bythe refrigerant path 202A to the inlet of the evaporating section 251Aof the process air cooler 300, and in the middle of the refrigerant path202A and in the vicinity of the inlet of the evaporating section 251A isprovided the throttle 230A. FIG. 29 shows only one throttle for the heatpump HPA system, but any number of throttles more than one may beprovided depending on the number of evaporating sections 251A orcondensing sections 252A.

Liquid refrigerant exiting the refrigerant condenser (heater viewed fromregeneration air) 220A in the state of the first condensing pressure, isdecreased in pressure by the throttle 230A to the third pressure, to beexpanded, and part of the refrigerant evaporates (flushes). Therefrigerant, mixture of liquid and gas, reaches the evaporating section251A, where liquid refrigerant flows while wetting the inner walls ofthe tubes of the evaporating section, is evaporated, and cools theprocess air flowing in the first compartment.

The evaporating section 251A and condensing section 252A are formed ofan integral tube. That is, they constitute an integral path, andtherefore evaporated refrigerant gas (and unevaporated refrigerantliquid) flows into the condensing section 252A, and is deprived of ownheat by outside air flowing in the second compartment, to be condensed.

In the first compartment, process air A flows in the first compartment,in the direction perpendicular to the heat-exchanging tubes of theevaporating section 251A, to exchange heat with refrigerant, and outsideair B having the inlet temperature lower than the temperature of processair, flows, in the second compartment, in the direction perpendicular tothe heat-exchanging tubes of the condensing section 252A.

In FIG. 30, the first and second compartments are provided adjacent toeach other with a partition plate 301 disposed there between, and theevaporating section and condensing section are formed of an integralcontinuous heat-exchanging tube, but as shown in FIG. 3, the heatexchanger may be arranged such that the first and second compartmentsare separated and further the first and second paths are also separated.In this case, there is no difference in functions as a heat exchangerfrom that of FIG. 30.

The condensing section 252A is connected, by the refrigerant liquid pipe203A, through the throttle 240A to the refrigerant evaporator (coolerviewed from process air) 210A. The pressure is reduced by the throttle240A from the third pressure to the first evaporating pressure. Thethrottle 240A may be disposed anywhere from a place immediately afterthe condensing section 252A to the inlet of the refrigerant evaporator210A, but if it is disposed immediately before the inlet of therefrigerant evaporator 210A, thermal insulation of piping can bethinner. The refrigerant liquid condensed in the condensing section 252Ais reduced in pressure at the throttle 240A and expanded to lower thetemperature, enters the refrigerant evaporator 210A to be evaporated,and cools process air by the evaporating heat.

Here, an orifice of constant opening is usually employed for thethrottle 240A. In addition to this fixed throttle, between the throttle240A and the evaporator 210A may be provided an expansion valve 270A,and a temperature sensor (not shown) may be attached to theheat-exchanging section of the refrigerant evaporator 210A or therefrigerant outlet of the refrigerant evaporator 210 A so as to detectthe superheating temperature, for adjustment of the opening of theexpansion valve 270A. In this way, excessive refrigerant liquid supplyto the refrigerant evaporator 210A will be avoided, resulting inavoiding intake of unevaporated refrigerant to the compressor 260A.

The refrigerant evaporated to be gasified in the refrigerant evaporator210A is introduced to the suction side of the refrigerant compressor260A, and the foregoing cycle is repeated.

The heat pump HPB has quite the same functions as those of the heat pumpHPA, except that its operating pressures (evaporating pressure andcondensing pressure) are lower than those of the heat pump HPA. Also,the second evaporator 210B is disposed downstream of the process airflow from the first evaporator 210A, and the second condenser 220B isdisposed upstream of the regeneration air flow from the first condenser220A. To the evaporating section 251A is connected the refrigerant path202A for the refrigerant flow from the first condenser 220A, and to theevaporating section 251B is connected the refrigerant path 202B for therefrigerant flow from the second condenser 220B.

In the structure described above, process air A flows, in the firstcompartment, in the direction perpendicular to the heat-exchangingtubes, in contact with the evaporating sections 251A, 251B in thisorder, to exchange heat with refrigerant, and outside air B having theinlet temperature lower than that of process air, flows, in the secondcompartment, in the direction perpendicular to the heat-exchangingtubes, in contact with the condensing sections 252B, 252A in this order.In this case, the evaporating pressure or the evaporating temperature isreduced from high to low in order from 251A to 251B in the evaporatingsection, and raised from low to high in order from 252B to 252A in thecondensing section. That is, the process air cooler 300 has twoevaporating pressures of the third and the fourth pressures ofrefrigerant used for cooling process air A, and has two condensingpressures of refrigerant cooled and then condensed by outside air B as acooling fluid, corresponding to the foregoing evaporating pressures.

Thus, noting the flow of process air A and outside air B, they exchangetheir heat, so to speak, in counterflow manner, thereby effecting aremarkably high heat exchange efficiency of, for example, 80% or higher.

Next, referring to FIG. 32, functions of the heat pumps HPA and HPB willbe described. FIG. 32 shows Mollier charts of the systems using HFC 134a as refrigerant. In these charts, the horizontal axis represents theenthalpy and the vertical axis the pressure. FIG. 32(a) is a Mollierchart for the first heat pump HPA, and FIG. 32(b) a Mollier chart forthe second heat pump HPB.

In the FIG. 32(a), the point a represents the state at the refrigerantoutlet of the cooler 210A shown in FIG. 29, in the state of saturatedgas. The pressure as a first evaporating pressure is 6.4 kg/cm², thetemperature as a fist evaporating temperature 23° C., and the enthalpy150.56 kcal/kg. A state in which this gas is compressed by thecompressor 260A, that is, the state of the discharge port of thecompressor 260A, is shown by point b. In this state, the pressure as afirst condensing pressure is 19.3 kg/cm², and the temperature issuperheated to 78° C.

This refrigerant gas is cooled in the heater (refrigerant condenser)220A and reaches the point c on the Mollier chart. This point representsthe state of saturated gas; the pressure is 19.3 kg/cm² and thetemperature as the first condensing temperature is 65° C. The gas isfurther cooled at this pressure, condenses, and reaches the point d.This point represents the state of saturated liquid; the pressure andthe temperature are the same as those of the point c, and the pressureis 19.3 kg/cm², the temperature 65° C., and the enthalpy 122.97 kcal/kg.

The state of one part of refrigerant liquid, which is reduced inpressure at the throttle 230A and flows in the evaporating section 251A,is represented by the point e on the Mollier chart. The temperature as afirst intermediate temperature is 40° C., and the pressure as a firstintermediate pressure is a saturation pressure corresponding to thetemperature of 40° C.

At the point e, the refrigerant is in the state of a mixture of liquidand gas in which part of the liquid is evaporated (flushed). Therefrigerant liquid is evaporated in the evaporating section at asaturation pressure as the first intermediate pressure, and reaches thepoint f intermediate between the saturated liquid line and saturated gasline for the pressure.

The refrigerant in this state flows into the condensing section 252A. Inthe condensing section, the refrigerant is deprived of heat by outsideair flowing in the second compartment, and reaches the point g. Thispoint is on the saturated liquid line in the Mollier chart. Thetemperature is approximately 40° C. This refrigerant liquid passesthrough the throttle 240A and reaches the point j. The pressure at pointj is the first evaporating pressure of this invention and is asaturation pressure of 6.4 kg/cm² at 23° C.

Here, the refrigerant is in the state of a mixture of liquid and gas.The refrigerant deprives process air of its heat in the cooler(refrigerant evaporator) 210A, evaporates to be a saturated gas in thestate of the point a on the Mollier chart, and is taken into thecompressor 260A again, repeating the foregoing cycle.

Functions of the second heat pump HPB is quite the same, except that theheat pump HPB operates as a whole, generally at lower pressures (lowertemperatures) than those of the heat pump HPA. That is, the evaporatingpressure as a second evaporating pressure in the second evaporator 210Bis 5.0 kg/cm², the evaporating temperature as a second evaporatingtemperature is 15° C., the condensing pressure as a second condensingpressure in the second condenser 220B is 14.8 kg/cm², the condensingtemperature as a second condensing temperature is 54° C., and theevaporating or condensing temperature as a second intermediatetemperature in the condensing section 251B or the condensing section252B is 36° 0C.

As described above, since within the heat exchanger 300 e, refrigerantevaporates in each evaporating section and condenses in each condensingsection while heat-exchange is performed by evaporating heat transferand condensing heat transfer, heat transfer coefficient is very high.Further, process air is cooled in the first compartment 310 from ahigher temperature to a lower temperature by temperatures of 40° C. and36° C. arranged in rows as it flows from the upper side to the lowerside in the Figure, so that heat exchange efficiency can be improvedcompared with cooling at a temperature of, for example, 40° C. The sameis true for the condensing section. That is, outside air (regenerationair) is heated in the second compartment 320 from a lower temperature toa higher temperature by temperatures of 36° C. and 40° C. arranged inrows as it flows from the lower side to the upper side in the Figure, sothat heat exchange efficiency can be improved, compared with heating ata temperature of, for example, 40° C.

In addition, in the case where the compression heat pump HPA includingthe compressor 260A, heater (refrigerant condenser) 220A, throttle, andcooler (refrigerant evaporator) 210A, is provided without heatexchangers 300 e, the enthalpy difference available in the cooler(evaporator) in returning refrigerant in the state of the point d in theheater (condenser) 220A through the throttle, is only 27.59 kcal/kg,while in the case of this embodiment where the heat exchanger 300 isprovided, the enthalpy difference is 150.56−113.51=37.05 kcal/kg,therefore gas volume circulated to the compressor for the same coolingload and thus required power (even if the temperature lift is the same)can be decreased by as much as 26%. Oppositely saying, cooling effectachievable for the same power can be enhanced by as much as 34%. Thatis, even though the compressor 260A is of a single stage type, it isable to act as a device similar to that of a multi-stage type and havingan economizer for removing flush gas in the intermediate stage. Indeed,the compressor in this embodiment does not need to remove flush gas inthe higher stage, thereby effecting a higher COP than a two-stage type.

The same is true for the second heat pump HPB. As shown in FIG. 32(b),gas volume circulated to the compressor for the same cooling load andthus required power (even if the temperature lift is the same), can bedecreased by as much as 18%. Oppositely saying, cooling effectachievable for the same power can be enhanced by as much as 21%. Also,temperature lift pumped up in the cooling cycle is 65−23=42° C. for thefirst heat pump HPA, and 54−15=39° C. for the second heat pump HPB.Temperature lift in case of one heat pump amounts to 65−15=50° C.,therefore the temperature lift in this embodiment is much smaller. Thus,the process air cooler 300 e is capable of improving the COP of the heatpump, in combination with reduced refrigerant flow rate per requiredcooling load or heating load.

Though in the foregoing description, as a preferable embodiment, thecondenser 220A is connected to the evaporating section 251A and thecondenser 220B to the evaporating section 251B, the condenser 220A mayhowever, be connected to the evaporating section 251B, and the condenser220B to the evaporating section 251A.

Next, referring to FIG. 33, the dehumidifying air conditioner of anotherembodiment of this invention will be described. FIG. 33 is an enlargedflow chart showing only the process air cooler 300 e 1 and its vicinityin the dehumidifying air conditioner, the other structures are the sameas in FIG. 29.

This heat exchanger or the process air cooler 300 e 1, like the heatexchanger in FIG. 29, is provided with a plurality of heat-exchangingtubes approximately horizontally which go through the first and secondcompartments 310 b, 320 b and the partition wall 301 and through whichrefrigerant 250 flows, except that in the first heat pump HPA system,the number of evaporating sections 251A passing through the firstcompartment is not one, but they are plurality, arranged in thedirection of the process air flow (three sections of 251A1, 251A2, 251A3shown in FIG. 33), and the section passing through the secondcompartment is composed of a plurality of condensing sections 252A1,252A2 and 252A3 arranged in the direction of the regeneration air flow,corresponding to the evaporating sections. The evaporating sections251A1, 251A2 and 251A3 are provided with the respective throttles 230A1,230A2 and 230A3 in the paths branched off from the one header 235Aprovided in the refrigerant path 202A. The condensing sections 252A1,252A2 and 252A3 are provided with the respective throttles 240A1, 240A2and 240A3, and they are joined to one header 245A, which is connected tothe refrigerant path 203A. These evaporating sections 251A1, 251A2,251A3 are arranged in rows in this order along the process air flow, andthe condensing sections 252A3, 252A2 and 252A1 in rows in this orderalong the regeneration air flow. They may be arranged such that aplurality of evaporating sections 240A11, 240A12, 240A13 . . . , aredisposed in the direction perpendicular to the process air flow for onethrottle, for example, 240A1, depending on the length of the section,cross sectional compartment of the passage, and refrigerant flow rate asappropriate.

The same is true for the second heat pump HPB. The evaporating sections251B1, 251B2 and 251B3 are arranged in rows in this order along theprocess air flow, downstream of the evaporating section 251A3, and thecondensing sections 252B3, 252B2 and 252B1 in rows in this order alongthe regeneration air flow, at the upstream side from the condensingsection 252A3.

In the structure described above, process air A flows, in the firstcompartment, in the direction perpendicular to the heat-exchangingtubes, in contact with the evaporating sections 251A1, 251A2, 251A3,251B1, 251B2 and 251B3 in this order, to exchange heat with refrigerant,and outside air B having the inlet temperature lower than that ofprocess air, flows, in the second compartment, in the directionperpendicular to the heat-exchanging tubes, in contact with thecondensing sections 252B3, 252132, 252B1, 252A3, 252A2 and 252A1 in thisorder. In this case, the evaporating pressure (temperature) or thecondensing pressure (temperature) of refrigerant, which is determinedfor each section grouped by a throttle, is lowered from high to low inthe evaporating sections of 251A1, 251A2, 251A3, 251B1, 251B2 and 251B3in this order, and raised from low to high in the condensing sections of252B3, 252B2, 252B1, 252A3, 252A2 and 252A1 in this order. That is, theprocess air cooler 300 e 1 has a plurality of evaporating pressures ofrefrigerant used for cooling process air A, for each of the first andsecond heat pumps, and has a plurality of condensing pressures ofrefrigerant cooled and then condensed by outside air B as a coolingfluid, corresponding to the foregoing evaporating pressures.Accordingly, this plurality of the evaporating pressures or thecondensing pressures is arranged in order of intensity.

Thus, noting the flow of process air A and outside air B, because of thetemperature difference in the heat pumps and temperature gradientbetween the plurality of the evaporating sections or the condensingsections within each heat pump, they exchange their heat, so to speak,in counterflow manner, thereby effecting remarkably high heat exchangeefficiency of, for example, 80% or more.

Now, further detailed description will be made on the plurality ofevaporating pressures arranged in order of intensity. The evaporatingpressures in the plurality of evaporating sections 251A1, 251A2 and251A3 are able to take different values, respectively, as a result ofseparate throttles 230A1, 230A2 and 230A3 at the inlets of theevaporating sections, and process air, which flows in the firstcompartment 310 in contact with the evaporating sections 251A1, 251A2and 251A3 in this order, is deprived of its sensible heat, so thattemperature from the inlet toward the outlet is lowered. As a result,the evaporating pressures within the evaporating sections 251A1, 251A2and 251A3 are reduced in this order, therefore the evaporatingtemperatures will be arranged in order.

Quite similarly, the condensing temperatures are arranged from a lowertemperature to a higher temperature in order of the sections 252A3,252A2 and 252A1, and like the evaporating sections, the condensingsections, each of which are provided with separate throttles 240A3,240A2, 240A1, respectively, are able to have separate condensingpressures or condensing temperatures, therefore as a result of outsideair flowing from inlet of the second compartment toward the outlet incontact with the condensing sections 252A3, 252A2 and 252A1 in thisorder, the condensing pressures will be arranged in order. The same istrue for the second heat pump HPB system. Therefore, noting the processair A and outside air B, the so-called counterflow type heat exchangercan be formed as described above, thereby achieving high heat exchangeefficiency.

Next, referring to FIG. 34, functions of the heat pumps HPA, HPB will bedescribed. FIG. 34 shows Mollier charts of the systems using HFC 134 aas refrigerant. In these charts, the horizontal axis represents theenthalpy and the vertical axis the pressure. FIG. 34(a) is a Mollierchart for the heat pump HPA, and FIG. 34(b) a Mollier chart for the heatpump HPB.

Referring to FIG. 34(a), the point a represents the state at refrigerantoutlet of the cooler 210A shown in FIG. 29, that is, in the state ofsaturated gas. The pressure is 6.4 kg/cm² and the temperature is 23° C.A state in which this gas is compressed by the compressor 260A, that is,the state of the discharge port of the compressor 260A, is shown bypoint b. In this state, the pressure is 19.3 kg/cm² and the temperatureis 78° C.

This refrigerant gas is cooled in the heater (refrigerant condenser)220A and reaches the point c on the Mollier chart. The pressure of thispoint is 19.3 kg/cm² and the temperature is 65° C. The refrigerant isfurther cooled and then condensed, and reaches the point d. This pointrepresents the state of saturated liquid; the pressure and thetemperature are the same as those of the point c, and the pressure is19.3 kg/cm², the temperature 65° C.

The state of one refrigerant, part of refrigerant liquid, which isreduced in pressure at the throttle 230A1 and flows in the evaporatingsection 251A1, is represented at the point e1 on the Mollier chart. Thetemperature is approximately 43° C. The pressure is one of the pluralityof different pressures of this invention, a saturation pressurecorresponding to the temperature of 43° C. Likewise, the state ofanother refrigerant which is reduced in pressure at the throttle 230A2and flows in the evaporating section 251A2, is represented at the pointe2 on the Mollier chart; the temperature is 41° C. and the pressure isone of the plurality of different pressures of this invention, asaturation pressure corresponding to the temperature of 41° C. Likewise,the state of another refrigerant which is reduced in pressure at thethrottle 230A3 and flows in the evaporating section 251A3, isrepresented at the point e3 on the Mollier chart; the temperature is 39°C. and the pressure is one of the plurality of different pressures ofthis invention, a saturation pressure corresponding to the temperatureof 39° C.

At any one of points e1, e2 or e3, the refrigerant is in the state of amixture of liquid and gas in which part of the liquid is evaporated(flushed). The refrigerant liquids each evaporate within the respectiveevaporating section at one of the foregoing respective plurality ofdifferent pressures, and reach the points f1, f2 and f3 intermediatebetween the saturated liquid lines and saturated gas lines for therespective pressures, respectively.

The refrigerants in these states flow in the condensing sections 252A1,252A2 and 252A3. In the condensing sections, the refrigerants aredeprived of heat by outside air flowing in the second compartment, andreach the points g1, g2 and g3, respectively. These points are on thesaturated liquid lines in the Mollier chart. The temperatures are 43°C., 41° C. and 39° C., respectively. These refrigerant liquids passthrough the throttles and reach the points j1, j2 and j3, respectively.The pressures at these points are a saturation pressure of 6.4 kg/cm² at23° C.

Here, the refrigerants are in the state of mixtures of liquid and gas.These refrigerants are joined to one header 245A, and the enthalpy thereis an average of enthalpies of points j1, j2 and j3 which are weightedby the corresponding refrigerant flow rates, respectively.

This refrigerant deprives process air of its heat in the cooler(refrigerant condenser) 210A, evaporates to be turned into saturated gasin the state of the point a on the Mollier chart, and is taken into thecompressor 260A again, resulting in a repetition of the foregoing cycle.

For the heat pump HPB, like the heat pump HPA, the condensingtemperature is 54° C. in the condenser 220B, and the temperatures of thepoints g1′, g2′ and g3′ corresponding to the points g1, g2 and g3 of theheat pump HPA are, for example, 37° C., 35° C. and 33° C., respectively,as shown in FIG. 34(b). The evaporating temperature of the evaporator210B is 15° C.

As described above, since within the heat exchanger 300 e 1, refrigerantevaporates in each evaporating section and condenses in each condensingsection while heat-exchange is performed by evaporating heat transferand condensing heat transfer, heat transfer coefficient is very high.Further, process air is cooled in the first compartment 310 from ahigher temperature to a lower temperature by temperatures of 43° C., 41°C., 39° C., 37° C., 35° C. and 33° C. arranged in rows as it flows fromthe upper side to the lower side in the figure, so that heat exchangeefficiency can be improved in comparison with cooling by one temperaturefor each heat pump of, for example, 40° C. and 36° C. The same is truefor the condensing section. That is, outside air (regeneration air) isheated in the second compartment 320 from a lower temperature to ahigher temperature by temperatures of 33° C., 35° C., 37° C., 39° C.,41° C. and 43° C. arranged in rows as it flows from the lower side tothe upper side in the Figure, so that heat exchange efficiency can beimproved, in comparison with heating by one temperature for each heatpump of, for example, 36° C. and 40° C.

As described above, the dehumidifying air conditioner of this embodimentis characterized in that it is provided with a process air cooler,process air is cooled by evaporation of refrigerant in the process aircooler, and the evaporated refrigerant is cooled by cooling fluid, tocondense. Therefore, evaporating heat transfer and condensing heattransfer of a high heat transfer coefficient can be utilized, thusachieving heat transfer between process air and cooling fluid, with ahigh heat transfer coefficient. Further, heat transfer between processair and cooling fluid is performed through refrigerant, therebyproviding a simple arrangement of components of the dehumidifying airconditioner. Furthermore, heat-exchange between process air and coolingfluid is formed into the so-called counterflow and a first and secondheat pumps are provided, so that it is possible to provide adehumidifying air conditioner having reduced temperature (thermal) liftsand a high COP as well as compact size.

Referring to FIGS. 35 and 36, the structure and arrangement will bedescribed of a dehumidifying air conditioner as a dehumidifier of anembodiment of this invention. FIG. 35 is a schematic front sectionalview of the dehumidifying air conditioner, and FIG. 36 is a flow chartof the dehumidifying air conditioner. The flow chart of FIG. 36 isdifferent from that of FIG. 29 in that the blower 102 is disposed, inFIG. 36, in the vicinity of the discharge port rather than the vicinityof the intake port, but otherwise is approximately the same. That is,the blower 102 among the devices constituting the dehumidifying airconditioner, is enclosed in the vicinity of the discharge port 106 inthe cabinet 700. The cabinet 700 is formed in the shape of a rectangularhousing made of, for example, sheet steel, and on one side of thecabinet at the lower portion is opened an intake port 104 for drawing(RA) process air a from the air conditioning space 101. In the openingof the intake port 104 is provided a filter 501 for preventing ingressof dust from the air conditioning space into the apparatus.

Vertically downwardly of the filter 501 is disposed, through adownwardly vertically running passage 107, a desiccant wheel 103 as themoisture adsorption device filled with desiccant (drying agent) as shownin FIG. 16. The desiccant wheel 103 is connected, through a belt orchain, etc, to an electric motor 105 as a driver disposed in thevicinity thereof with rotational shaft AX in the vertical direction forrotation at a speed as low as approximately one revolution per severalminutes.

When the desiccant wheel 103 is disposed for rotation about the verticalrotational shaft approximately in a horizontal plane, process air Aflowing along the downwardly running passage 107 is able to pass throughthe semi-circular region of the circular desiccant wheel 103, or aprocess air zone, without changing the direction, simplifying theprocess air passage and thus providing compact size. Further, filling ofdesiccant into the desiccant wheel 103 is easier and a more uniformdistribution of desiccant is achieved in the desiccant wheel 103.

Downwardly of the desiccant wheel 103 and vertically downwardly of theprocess air zone into which process air flows, is disposed a firstcompartment 310 of the process air cooler 300, which compartment 310comprises an evaporating section 251A on the vertical upper side and anevaporating section 251B on the vertical lower side. Process air passesthrough the evaporating section 251A and evaporating section 251B inthis order. A passage 109 connecting the desiccant wheel 103 and thefirst compartment 310 is formed as a passage running verticallydownwardly and connecting the desiccant wheel 103 disposed horizontallyin this embodiment and tubes (and fins attached to these tubes) of thecondensing section 251A also disposed horizontally.

Vertically downwardly of the first compartment 310 are disposed arefrigerant evaporator 210A as the first heat exchanger on the upperside and a refrigerant evaporator 210B as the second heat exchanger onthe lower side, with cooling pipes for refrigerant in the horizontaldirection. Process air A passes through the refrigerant evaporator 210Aand refrigerant evaporator 210B in this order. In this embodiment, thepassage 110 is a space between the first compartment 310 and therefrigerant evaporator 210A, but the two components are disposedclosely, so that there exists little space between them. Verticallydownwardly of the refrigerant evaporator 210 runs a passage 111A, whichintroduces process air A laterally horizontally and is connected,through a humidifier 115 at the bottom of the passage 111A, to thepassage 111B disposed just adjacent to the passage 107, passage 109, andpassage 110. The passage 111B is running vertically upwardly.

At the top of the passage 111B is attached a blower 102 as the firstblower, which draws process air A introduced to the passage 111B andsupplies it (SA) to the air conditioning space 101 from the opening inthe top surface of the cabinet 700, or the discharge port 106. Thedischarge port 106 is formed on the top surface of the cabinet 700 onthe vertical extended line of the passage 111B.

On the other hand, at the lower one side of the cabinet 700 is opened anintake port 141 for drawing OA outside air, or regeneration air B, inwhich is provided a filter 502 for preventing ingress of dust from inthe outside air, or regeneration air B.

Regeneration air B, after passing through the filer 502, enters thepassage 124, and is fed laterally horizontally along the passage 124 andthen vertically upwardly. Above the passage 124 is disposed a processair cooler 300 as the third heat exchanger, and regeneration air passesthrough the condensing section 252A and condensing section 252B in thisorder vertically upwardly. Vertically above the process air cooler 300are disposed a refrigerant condenser 220B as the second heat exchangerand refrigerant condenser 220A as the second heat exchanger. In therefrigerant condenser 220A and the refrigerant condenser 220B arerespectively disposed heat exchanger tubes approximately horizontally.

A space vertically below the refrigerant condenser 220 and between therefrigerant condenser 220 and the desiccant wheel 103, constitutes apassage 127, via which regeneration air B is introduced to the otherhalf region of the desiccant wheel 103 as a regeneration air zone withrespect to the foregoing half region on the process air A side. Thespace vertically above the half region of the desiccant wheel 103 forthe regeneration air B to pass through, constitutes a passage 128, inwhich a blower 140 as the second blower is disposed with the intake portfacing this space.

The discharge port of the blower 140, facing sideward, is connected toanother discharge port 142 opened on one side of the cabinet 700 at theupper portion, and regeneration air B is discharged EX from thedischarge port 142.

On the other hand, the refrigerant gas pipe 201A for feeding refrigerantgas delivered from the compressor 260A to the condenser 220A, runslaterally to approach the side of the cabinet, then upwardly, andlaterally again in the direction away from the side of the cabinet, tobe connected to the refrigerant condenser 220A. The refrigerant pipe202A exiting the outlet of the refrigerant condenser 220A runs laterallythrough the path 109, and downwardly at the path 119. In the middle ofthis downwardly running pipe is provided a header incorporating athrottle 230A, which decreased the pressure of refrigerant and isconnected to the evaporating section 251A. Refrigerant decreased inpressure through the throttle 240A in the header, is fed to theevaporating section 251A composed of a plurality of tubes, andevaporates. Then, another header for inducting refrigerant condensed inthe condensing section 252A and having a throttle 240A therein, isprovided in the middle of a refrigerant pipe 203A running downwardlyfrom the outlet of the condensing section 252A.

The refrigerant liquid pipe 203A runs further laterally, then verticallydownwardly again, and laterally through the passage 111A, below therefrigerant evaporator 210B, and lastly rises to be connected to therefrigerant evaporator 210A. Refrigerant is decreased in pressure at anexpansion valve 270A in the refrigerant pipe running laterally below therefrigerant evaporator 210B, and proceeds to the refrigerant evaporator210A through the refrigerant liquid pipe 204A downstream from theexpansion valve 270A. Further, the refrigerant pipe 205A connecting therefrigerant evaporator 210A and the compressor 260, runs laterally fromthe refrigerant evaporator 210A, and then downwardly.

As described above, the passages 107, 109, 110 of process air A runvertically downwardly and the passage 111B vertically upwardly; thepassages 124, 126, 127 of regeneration air run vertically upwardly; theintake port 104 and discharge port 106 of process air are disposed onthe top surface of the apparatus; and the intake port 141 ofregeneration air is disposed in the vicinity of the bottom of theapparatus, and the discharge port 142 in the vicinity of the top surfaceof the apparatus, so that the process air passage is in the shape of aletter U and the regeneration air passage is formed straight, both ofwhich are of simplified shape.

Further, the blower 102, blower 140, desiccant wheel 103, refrigerantcondenser 220A/220B, process air cooler 300, refrigerant evaporator210A/210B are arranged vertically in the upper and lower positions in aorderly manner, providing compact size and a smaller installation area.Further, process air A and regeneration air B passing through thedesiccant wheel 103, need not change their direction immediately beforeand after the desiccant wheel 103, proving a smooth flow.

Functions of the dehumidifying air conditioner of an embodiment of thisinvention as shown in FIG. 35 are substantially the same as thosedescribed on the humid air diagram in FIG. 31. Also, the refrigerantflow between devices and functions of the heat pumps HPA, HPB aresubstantially the same as those described in FIG. 29.

Referring to FIG. 37, the structure of the dehumidifying air conditionerof another embodiment of this invention will be described. In theFigure, process air drawn from the air conditioning space through theintake port 104 at the top of the cabinet 700 and through the filter 501into the cabinet, passes through the downwardly running passage 107along the process air A path, to be drawn into the blower 102 forproviding process air A circulation and discharged from the dischargeport of the blower 102; then passes through the downwardly runningpassage 108, downwardly through the process air zone of the desiccantwheel 103 filled with desiccant, then passes through the downwardlyrunning passage 109, and continuos downwardly through the heat exchanger225 for collecting heat from process air A; then passes through thedownwardly running passage 110, and downwardly through the heatexchanger 116 for cooling process air; flows horizontally along thepassage 111A through the humidifier 115; and then passes through theupwardly running passage, and through the discharge port 106 at the topof the cabinet 700 to be returned to the air conditioning space.

Also, regeneration air B drawn through the intake port 141 on one sideof the lower portion of the cabinet 700, via the filter 502, into thecabinet 700, flows along the regeneration air B path and along thepassage 124 to be inducted upwardly; then passes through the heatexchanger 131 for heating regeneration air B before ingress of thedesiccant wheel 103, upwardly; then passes through the upwardly runningpassage 127, and through the regeneration air zone of the desiccantwheel 103, upwardly; then passes through the upwardly running passage128 to be drawn into the blower 140 for providing the regeneration air Bcirculation and discharged from the discharge port of the flower 140;and then is discharged to the outside from the discharge port 142 at thetop of the cabinet 700.

Regarding arrangement inside the actual dehumidifying air conditioner,the blowers 102, 140 are disposed at the very top of the apparatus. Theblower 140 is mounted on the underside (on the inside of the apparatus)of the upper wall of the apparatus, while the blower 102 is mounted tothe mounting plate provided in the process air passage horizontally andhaving an opening of the same size as the discharge port of the blower102. The rotational axes of the blowers 102, 140 are disposed atapproximately the same height. Vertically downwardly of the blowers 102,140 is disposed the desiccant wheel 103 with the rotational shaft in thevertical direction. Also, downwardly of the desiccant wheel 103 aredisposed the heat exchanger 225 and the heat exchanger 131 horizontallyat the same height in a row. Further, downwardly of the heat exchanger225 is disposed the heat exchanger 116 horizontally.

A hot water medium pipe 151 for inducting the hot medium, or hot water,is connected to the hot medium supply port 42 of the refrigerantcondenser (not shown in FIG. 37) of the outside heat pump (not shown inFIG. 37), and the hot water inlet of the heat exchanger 131. The heatexchanger 131 is counterflow type heat exchanger configured such thathot water and regeneration air B are adapted to exchange heat incounterflow relation. The hot water outlet of the heat exchanger 131 isconnected, by a hot water pipe, to the hot water inlet of the heatexchanger 225. The heat exchanger 225 is also configured such that hotwater and process air A are adapted to exchange heat in counterflowrelation. The hot water outlet of the heat exchanger 225 is connected,by a hot water pipe 152, to a hot medium return port 43 of therefrigerant condenser of the outside heat pump. Hot water is returned tothe refrigerant condenser, to be heated by condensation of refrigerantin the refrigerant condenser, and then inducted to the heat exchangers131 and 225, to be circulated.

A cold water pipe 161 for inducting the cold medium, or cold water, isconnected to the cold medium supply port 40 of the refrigerant condenser(not shown in FIG. 37) of the outside heat pump, and the cold waterinlet of the heat exchanger 116. The heat exchanger 116 is configuredsuch that cold water and process air A as a heat-exchanging object areadapted to exchange heat in counterflow relation. The cold water outletof the heat exchanger 116 is connected, by a cold water pipe 162, to acold medium return port 41 of the cold evaporator of the outside heatpump. Cold water is returned to the refrigerant evaporator, to be cooledby evaporating the refrigerant in the evaporator, and then inducted tothe heat exchanger 116, to be circulated.

Next, referring to FIG. 37 again, functions of this embodiment will bedescribed. In the following description, temperature conditions areshown as an example.

First, regarding the process air A flow, process air of approximately27° C. is drawn from the air conditioning space, then adsorped of itsmoisture by desiccant in the desiccant wheel 103 which decreases itsabsolute humidity, and the heat of adsorption of the desiccant raisesthe dry bulb temperature, to approximately 50° C. This air is cooled bythe hot medium (decreased in temperature in the heat exchanger 130 asdescribed later) in the heat exchanger 225, with the absolute humiditykept constant, turned into air at approximately 38° C., and enters theheat exchanger 116.

There, it is cooled further by the cold medium and turned into air at15° C. This air makes an isoenthalpic change in the humidifier 115,absolute humidity is raised and the dry-bulb temperature is decreasedand is returned to the air conditioning space as a process air A ofappropriate humidity and appropriate temperature.

Next, regarding the regeneration air B flow, regeneration air B ofapproximately 32° C. drawn from the outside (outdoor) OA, exchanges heatin the heat exchanger 131 with the hot medium of a raised temperaturefrom the heat pump HP, and increases dry-bulb temperature, to be turnedinto air at approximately 70° C.

The hot medium decreased in temperature in the heat exchanger 131,raises its own temperature while cooling process air A, as describedabove. This effects heat collection for the hot medium. The hot mediumis returned with collected heat to the heat pump HP, to be heated there,and supplied to the heat exchanger 131 to heat regeneration air B. Asdescribed above, regeneration air B is heated from about 32° C. to about70° C., and of this temperature rise, the portion collected by the heatexchanger 225 from process air A amounts to the temperature rise fromabout 32° C. to about 46° C.

Regeneration air B heated up to 70° C. in the heat exchanger 131 asdescribed, passes through the passage 126 to the desiccant wheel 103,where it deprives the desiccant of moisture to regenerate it, raises itsown absolute humidity, and is decreased in dry-bulb temperature bymoisture removal heat of the desiccant. This air is drawn into theblower 140 for providing regeneration air B circulation, and thendischarged EX.

Now, with respect to the embodiment shown in FIG. 37, functions of theheat exchanger 131 and heat exchanger 225 will be described. First, inthe heat exchanger 131, the hot water medium heated up to about 75° C.by the heat pump, exchanges heat with outside air of about 32° C. usedfor regeneration air B in counterflow relation. The hot medium decreasesin temperature from about 75° C. to about 36° C. Meanwhile, theregeneration air B exchanging heat with the hot medium, raisestemperature from about 32° C. to about 70° C.

As described above, the hot medium cooled to about 36° C. exchanges heatin counterflow low relation with process air A. The hot medium is heatedfrom about 36° C. to about 47° C. Meanwhile, the process air Aexchanging heat with the hot medium, decreases in temperature from about50° C. to about 38° C.

In the embodiment shown in FIG. 37, the heat equivalent to the portionof total heat utilized in heating regeneration air B in the heatexchanger 131, can be collected from process air A in the heat exchanger225, thereby effecting increased heating capacity, improved efficiency,smaller-size of the apparatus, and thus cost reduction.

Further, as described above, the passages 107, 108, 109, and 110 ofprocess air A run vertically downwardly, the passage 111B verticallyupwardly, and the passages 124, 127, and 128 of regeneration air runvertically upwardly; the intake port 104, and discharge port 106 ofprocess air are disposed at the top of the apparatus, the intake port141 of regeneration air in the vicinity of the bottom of the apparatus,and the discharge port 142 at the top of the apparatus, so that thepassage of process air is in the shape of a letter U, and the passage ofregeneration air is straight, both of which are of simplified shape.

Furthermore, the blowers 102, 104, desiccant wheel 103, heat exchanger225, process air cooler 300, and heat exchanger 116 are arranged inorderly manner vertically in the upper and lower positions, therebyproviding a compact apparatus as well as smaller installation area.Moreover, process air A and regeneration air B passing through thedesiccant wheel 103, need not change their flow directions immediatelybefore and after the desiccant wheel 103, effecting a smooth flow.

Next, referring to FIG. 38, the structure of the dehumidifying airconditioner of another embodiment of this invention will be described.The same features as the embodiment shown in FIG. 37 are not repeatedand only the differences will be referred to.

In the embodiment shown in FIG. 38, the cold medium, in the state ofliquid, supplied from the cold medium supply port 40 of the heat pump(not shown), changes its phase within the heat exchanger 116, that is,evaporates to be gasified, cools process air, and the cold mediumreturns to the port 41 of the heat pump. On the other hand, the hotmedium, in the state of gas, supplied from the hot medium supply port 42of the heat pump, changes it phase within the heat exchanger 131, thatis, condenses to be liquefied, turns into the state of supercooling (orsubcooling/cooling lower than saturation temperature), and sent to theheat exchanger 225, and cools process air A in the heat exchanger 225.

The structure, functions, and effects of the dehumidifying airconditioner of an embodiment shown in FIG. 38, are the same as those ofthe dehumidifying air conditioner of this embodiment shown in FIG. 37,other than the foregoing description.

As described above, the dehumidifying air conditioner of an embodimentaccording to this invention is characterized by a dehumidifying airconditioner comprising a desiccant wheel 103 with the rotational axis AXdisposed in the vertical direction, wherein the process air passageincludes mainly a first passage portion running vertically downwardlyand a second passage portion running vertically upwardly, so that theprocess air flow passing through the apparatus, can be arranged mainlyin the vertical direction in orderly manner and main devices can bedisposed vertically in the upper and lower positions without need forprocess air to change its flowing directions before and after thedesiccant wheel, thus providing a compact apparatus as well as a smallerinstallation area, compared with a dehumidifying air conditionerincorporating a desiccant wheel with the rotational axis disposedhorizontally. The term, “mainly including”, means that the process airpassage or regeneration air passage in which main components such as thedesiccant wheel, heat exchanger, and condenser are provided, run, forexample, vertically downwardly, but they may transitionally runlaterally so as to take upward routes.

In the following, another embodiment of this invention will be describedwith reference to the drawings.

Referring to FIG. 39, an example of the mechanical structure andarrangement of the dehumidifying air conditioner will be described. Thisis appropriate for the structure of the apparatus described withreference to FIG. 5, except that in FIG. 5, a throttle 270 is added atthe upstream side of the refrigerant line from the refrigerantevaporator 210. In the Figure, devices constituting the apparatus areenclosed within the cabinet 700. The cabinet 700 is formed in the shapeof a rectangular box made of, for example, sheet steel, and on one sideof the cabinet at the lower portion is opened an intake port 104 fordrawing (RA) process air A from the air conditioning space 101. In theopening of the intake port 104 is provided a filter 501 for preventingingress of dust from the air conditioning space into the apparatus.Inside the filter 501 in the cabinet 700 is disposed a blower 102 as thesecond blower, and the intake port of the blower 102 is incommunication, through the filter 501, with an intake port 104 forprocess air A of the cabinet. Passage 107 is formed between intake port104 and intake port of blower 102.

The compressor 260 and a blower 140 as the first blower are arranged ina space in the lower section of the cabinet 700 in a row in placesapproximately horizontally sideward of the blower 102. High speed rotarymachines are disposed concentrated in one section, providing easysoundproofing. Also, immediately upwardly of the compressor 260 and theblower 140 is disposed the desiccant wheel 103 with the rotational axisin the vertical direction. Weighty compressor 260, blowers 102, 140,driving motor, and desiccant wheel 103 are disposed relatively lowerpositions, thus lowering the center of gravity of the apparatus. Thedesiccant wheel 103 is connected, for rotation at a speed as low as onerevolution per several minutes by a belt, chain, etc, to the driverdisposed in the vicinity thereof with the rotational axis in thevertical direction.

In this way, the desiccant wheel 103 is disposed for rotation about therotational axis in the vertical direction in an approximately horizontalplane, therefore the total height of the apparatus can be kept low,effecting compact size. Further, filling of desiccant in the desiccantwheel 103 is easier and uniform distribution of desiccant in thedesiccant wheel 103 can be achieved. Moreover, almost all the movingelements or the rotary machines, such as the blowers 102, 140, and thedesiccant wheel 103, including the weighty compressor 260, are arrangedin the lower section of the apparatus or the bottom of the cabinet, thatis, near the base, preventing adverse effects of vibration andincreasing stability of installation.

The discharge port of the blower 102 is connected to the desiccant wheel103 by a passage 108. The passage 108, and the above described passage107 is configured such that they are separated from other portions withpartitions made of, for example, sheet steel the same as that of thecabinet 700. It is into the approximately half (semi-circular) region ofthe circular desiccant wheel 103 as a process air zone that process airA flows.

Vertically upwardly of the desiccant wheel 103, especially, upwardly ofthe half (semi-circular) region into which process air A flows, isdisposed a first compartment 310 of the process air cooler 300, or anevaporating section 251. A passage 109 connecting the desiccant wheel103 and the first compartment 310 is formed as a narrow space betweenthe desiccant wheel 103 disposed horizontally in FIG. 39 and tubes (andfins on the tubes) of the evaporating section 251 also disposedhorizontally. Upwardly of the first compartment 310 is disposed arefrigerant evaporator 210 as the second heat exchanger with coolingpipes for refrigerant in the horizontal direction. In the example shownin FIG. 39, a passage 110 is the space between the first compartment 310and the refrigerant evaporator 210, but these two elements are disposedclose to each other, so that there exists little space. Upwardly of therefrigerant evaporator 210 lies a passage 111, and the opening forsupplying SA process air A to the air conditioning space 101, or adischarge port 106, is formed on the top of the cabinet 700.

As described above, it can be seen that the intake port 104 for processair A is disposed in the vicinity of the bottom of the cabinet 700(actually on one side thereof at the lower portion); the passages 109,110, 111 of process air passing through the process air side half of thedesiccant wheel 103, evaporating section 251 of the process air cooler300, and the refrigerant evaporator 210, are formed upwardly; and thedischarge port 106 of process air A is disposed on the top of thecabinet 700.

On the other hand, on one side of the cabinet 700 at the upper portionis opened an intake port 141 for drawing OA regeneration air B, in whichis provided a filter 502 for preventing ingress of dust from the outsideair, or regeneration air B. The space inside the filter 502 constitutesa passage 124, and a cross flow heat exchanger 121 is disposed, definingpart of the space. At the side of one outlet of the heat exchanger 121is disposed a refrigerant condenser 220. The refrigerant condenser 220as a first heat exchanger with heat-exchanging tubes as a fluid passagedisposed approximately horizontally, is arranged in a row at the sameheight as the refrigerant evaporator 210. The outlet of the heatexchanger 121 is connected, by the passage 126, to the refrigerantcondenser 220.

The space below the refrigerant condenser 220 and between therefrigerant condenser 220 and the desiccant wheel 103, constitutes apassage 127, through which regeneration air B is inducted to the resthalf region as a regeneration air zone of the desiccant wheel 103 withrespect to the above described half region on the process air A side.The space below the half region, of the desiccant wheel 103, for theregeneration air B to pass through, constitutes a passage 128, and inthis space is disposed a blower 140 with the intake port facing thisspace.

The discharge port of the blower 140, facing sideward, is connected tothe heat exchanger 121 by a passage 129 defined vertically in thecabinet 700. Regeneration air B flowing in the passage 129 upwardlythrough the heat exchanger 121, passes through a passage 130 crossingthe above described passage 124 at the heat exchanger 121 to the spacedefined by the heat exchanger 121 and the cabinet 700, or a passage(part of the passage 130), and is discharged (EX) through a dischargeport 142 opened on the top of the cabinet 700.

As described above, it can be seen that the intake port 141 forregeneration air B is disposed in the vicinity of the top of the cabinet700 (actually on one side thereof at upper portion); the passages 127,128 for regeneration air B passing through the refrigerant condenser,and the regeneration air side half of the desiccant wheel 103, areformed downwardly; the passage 129 for regeneration air B exiting theblower 140 is formed mainly upwardly; and the discharge port 142 ofregeneration air B is disposed on the top of the cabinet 700.

Further, on one side of the cabinet 700 and approximately directly abovethe intake port 104 for process air, is opened an intake port 166 fordrawing OA outside air C as a cooling fluid. In this opening is provideda filter 503 for preventing ingress of dust in the outside air C intothe apparatus. A passage 171 is defined including the space inside thefilter 503, and upwardly of the space is disposed a humidifier 165approximately horizontally. The space above the humidifier 165constitutes a second compartment 320, in which is disposedheat-exchanging tubes of the condensing section 252 approximatelyhorizontally. The condensing section 252 and the foregoing evaporatingsection 251 is constituted by integral tubes. In the space above thecondensing section 252 is disposed a spray pipe 325, which is adapted tospray water over the tubes (and fins) of the condensing section 252. Thespray pipe 325 is provided with a regulating valve 326 so as to regulatethe amount of sprayed water properly, for example, to provide properwetness of the humidifier 165 or to inhibit excessive wetting.

The lower portion of the space defining the passage 171 forms a drainpan 173, to which is attached a discharge pipe 174 for dischargingexcessive water sprayed by the spray pipe 325 to the outside of thecabinet 700. The space above the second compartment 320 also serves as apassage 172, and upwardly of this space at the top of the cabinet 700,is opened an air discharge port 168. In the air discharge port 168 isprovided a blower 160 for discharging EX air.

On the other hand, a refrigerant gas pipe 201 for feeding refrigerantgas delivered from the compressor 260 to the refrigerant condenser 220,is provided, running laterally at the bottom of the cabinet and thenrising upwardly. At the outlet of the refrigerant condenser 220 isprovided a header 230 incorporating a throttle, through which condensedrefrigerant is decreased in pressure, to be inducted to the evaporatingsection 251. The refrigerant decreased in pressure by the throttle (notshown) incorporated in the header 230, is fed to the evaporating section251 composed of a plurality of tubes, to be evaporated. Next, a header240 for collecting refrigerants condensed in the condensing section 252,is provided at the outlet of the condensing section 252.

The refrigerant liquid pipe 203 rises from the header 240, andrefrigerant, decreased in pressure at the throttle provided near thehighest portion of the pipe, flows through the refrigerant liquid pipe204 to the refrigerant evaporator 210. Also, a refrigerant pipe 205connecting the refrigerant evaporator 210 and the compressor 260, isdisposed, running downwardly from the refrigerant evaporator 210.

As a result of the passage of process air A being disposed as describedabove, the location of the main devices associated with process air A issuch that with the desiccant wheel 103 as a base position, the blower102 is below the desiccant wheel 103, the process air cooler 300 isabove the desiccant wheel 103, and the refrigerant evaporator 201 isabove the process air cooler 300.

As a result of the passage of regeneration air B being disposed asdescribed above, the location of the main devices associated withregeneration air B is such that with the desiccant wheel 103 as a baseposition, the blower 140 is below the desiccant wheel 103, therefrigerant condenser 220 is above the desiccant wheel 103. In addition,process air and regeneration air passing through the desiccant wheelneed not change their flow direction before and after the desiccantwheel, providing a smooth flow.

Therefore, main devices are disposed vertically in the upper and lowerpositions in orderly manner, effecting compact size as well as a smallerinstallation area.

Next, referring to FIG. 40, the arrangement of the devices of adehumidifying air conditioner which is another embodiment of thisinvention will be described. This embodiment is appropriate for thestructure of the apparatus described with reference to FIG. 18. The samefeatures as the foregoing embodiment shown in FIG. 39 are omitted andonly the differences will be referred to.

In the embodiment shown in FIG. 39, the dehumidifying air conditioner isoperated mainly in the cooling operation mode, but in this embodiment,the air conditioner is configured so as to be operated mainly in theheating operation mode in addition to the cooling operation mode.

FIG. 40(a) is a schematic front view of the dehumidifying airconditioner of an embodiment of this invention. In the Figure, thedehumidifying air conditioner is characterized in that the refrigerantpipe around the compressor for refrigerant is provided with a four-wayvalve 265, the refrigerant pipe around the process air cooler 300 as athird heat exchanger is provided with four-way valve 280, and therefrigerant passage is provided with a discharge port 143 and athree-way valve 145, so that the dehumidifying air conditioner iscapable of heating operation in addition to cooling operation asdescribed above. Other components, passage, and their arrangement arethe same as described with respect to the embodiment of thedehumidifying air conditioner shown in FIG. 39.

In FIG. 40(a), the fluid flow in the four-way valves 265, 280, andthree-way valve 145 shows an instance in cooling operation. That is,refrigerant flows through the refrigerant evaporator 210, compressor260, refrigerant condenser 220, and the evaporating section 251 andcondensing section 252 of the process air cooler 300 in this order, andreturned to the refrigerant evaporator 210 for circulation. Also,regeneration air B exiting the blower 140 flows through the heatexchanger 121 to the discharge port 142. The three-way valve 145 is inthe position of opening the regeneration air side inlet of the heatexchanger 121. During cooling operation, the three-way valve 145 closesthe second discharge port 143.

FIG. 40(b) shows the refrigerant flow through the four-way valve 265 inthe heating operation, and FIG. 40(c) shows the refrigerant flow throughthe four-way valve 280 in the heating operation. The position of thethree-way valve 145 is shown in FIG. 40(a) by broken lines. That is,refrigerant flows through the refrigerant evaporator 210, evaporatingsection 251 of the process air cooler 300, condensing section 252 of theprocess air cooler 300, refrigerant condenser 220, and compressor 260 inthis order, and returns to the refrigerant evaporator 210 forcirculation. During the heating operation, the blower 160 is notoperated and no water is sprayed in the humidifier 165. Also, as thethree-way valve 145 is in the position of closing the inlet of the heatexchanger 121, regeneration air B exiting the blower 140 does not passthrough the heat exchanger 121, but is discharged from the seconddischarge port 143.

In the embodiment shown in FIG. 40, like the embodiment shown in FIG.39, the blowers 102, 140 and compressor 260 are disposed below thedesiccant wheel 103, and the refrigerant condenser 220 and refrigerantevaporator 210 are disposed above the desiccant wheel 103. In theprocess air cooler 300, process air A and cooling air (outside air C)exchange their heat through refrigerant; the process air A is cooled andthe cooling air (outside air C) is heated.

The embodiment shown in FIG. 40 is the same as the embodiment shown inFIG. 39 in that the intake port 104 of process air A is disposed in thevicinity of the bottom of the cabinet 700 (actually on one side thereofat the lower portion), and the discharge port 106 of process air A isdisposed on the top of the cabinet 700; that the process air passage isdisposed, running upwardly from the desiccant wheel 103 to the dischargeport 106; that the intake port 141 of regeneration air B is disposed inthe vicinity of the top of the cabinet 700 (actually at one side thereofat the upper portion), and the discharge port 142 of regeneration air Bis disposed on the top of the cabinet 700; the regeneration air passagesare disposed proceeding downwardly until they reach the blower 140 afterexiting the heat exchanger 121, and upwardly until they reach the heatexchanger 121 after exiting the blower 140; and that the compressor 260and blowers 102, 140 are disposed in the lowermost positions, and maindevices are disposed vertically in the upper and lower positions.

Next, referring to FIG. 41, arrangement of the devices of dehumidifyingair conditioner of another embodiment of this invention will bedescribed. The same features as the foregoing embodiment shown in FIG.39 are omitted and only the differences will be referred to. Thisembodiment is appropriate for the structure of the apparatus describedwith reference to FIG. 8.

The embodiment shown in FIG. 39 is arranged such that tubes 253A, 253B,253C constituting the process air cooler 300 equipped in thedehumidifying air conditioner, are disposed horizontally, and verticallyin rows, and the temperatures of refrigerant flowing in this tubes arethe same at the mouths of the heat-exchanging tubes.

On the other hand, the embodiment of the dehumidifying air conditionershown in FIG. 41 is arranged such that the temperatures, at the mouthsof the heat-exchanging tubes, of refrigerant flowing in theheat-exchanging tubes of the process air cooler 303 as the third heatexchanger, are the highest for the heat-exchanging tube 253A disposed inthe highest position, and are lowered toward the heat-exchanging tubesdisposed lower positions from the second tube 254B to the third tube253C. Therefore, heat exchange efficiency of the process air cooler 303can be enhanced.

No water is sprayed to the heat-exchanging tubes of the condensingsection 252 of the process air cooler 303. In the process air cooler303, process air A and regeneration air B exchange their heat throughrefrigerant; process air A is cooled and regeneration air B is heated.The blower 102 for process air is disposed directly below the desiccantwheel 103.

Regeneration air B is heated by the condensing section 252 of theprocess air cooler 303, and the passage of regeneration air B isdisposed proceeding downwardly, therefore the refrigerant condenser 220is disposed directly below the condensing section 252 of the process aircooler 303. No heat exchanger (numeral 121 in FIG. 39) is mounted, andthe intake port 141 for regeneration air B is provided on the top of thecabinet 700.

The compressor 260 is mounted at the bottom of the cabinet 700, anddisposed directly below the passage 129 of regeneration air proceedingupwardly.

In the embodiment shown in FIG. 41, like the embodiment shown in FIG.39, the blowers 102, 140 and compressor 260 are disposed below thedesiccant wheel 103, and the refrigerant condenser 220 and refrigerantevaporator 210 are disposed above the desiccant wheel 103. In theprocess air cooler 300, process air A and cooling air (outside air C)exchange their heat through refrigerant; the process air A is cooled andthe cooling air (outside air C) is heated. The refrigerant condenser220, process air cooler 303, and refrigerant evaporator 210 are disposedfrom the lower position to the upper position in this order.

In the embodiment shown in FIG. 41, the process air passage proceedsupwardly from the blower 102 to the discharge port 106, then downwardlyuntil it reaches the blower 140 after passing through the intake port141, and then upwardly until it reaches the discharge port 142 afterexiting the blower 140 horizontally and changing its direction by 90degrees. Also, the discharge port 106 of process air A is disposed onthe top of the cabinet 700, and the discharge port 142 of regenerationair B is disposed on the top of the cabinet 700.

Next, referring to FIG. 42, arrangement of the devices of dehumidifyingair conditioner of another embodiment of this invention will bedescribed. This embodiment is appropriate for the structure of thedehumidifying air conditioner described with reference to FIG. 29. Thesame features as the foregoing embodiments shown in FIG. 39 and FIG. 41,are omitted and only the differences will be referred to.

In the embodiment of the dehumidifying air conditioner shown in FIG. 42,the refrigerating cycle is composed of a high pressure cycle and a lowpressure cycle to improve heat exchange efficiency. In this case, therefrigerant evaporator 210 of the dehumidifying air conditioner in theembodiment shown in FIG. 41, is divided into two sections, a highpressure section 210A and a low pressure section 210B, and therefrigerant condenser 220 into a high pressure section 220A and a lowpressure section 220B, each constituting part of the high pressure cycleand the low pressure cycle. The process air cooler 303 as a third heatexchanger is divided into a high pressure section 303A with aheat-exchanging tube 235A through which refrigerant of a low pressurecycle flows, and a high pressure section with a heat-exchanging tube253B through which refrigerant of a high pressure cycle flows, andprovided with two compressors, a high pressure compressor 260A and a lowpressure compressor 260B, each constituting part of the high and lowpressure cycles.

The process air A passes through the blower 102, desiccant wheel 103,and evaporating section 251 of the process air cooler 303 in this order,and then the high pressure section 210A of the refrigerant evaporator210 to the low pressure section 210B, therefore the passage of processair A proceeds upwardly from the bottom to the top. In the evaporatingsection 251 of the process air cooler 303, it passes through from thehigh pressure section 303A to the low pressure section 303B. In theprocess air cooler 303, process air A and regeneration air B exchangetheir heat through refrigerant; process air A is cooled in theevaporating section 251 and regeneration air B is heated in thecondensing section 252.

Regeneration air B passes through the condensing section 252 of theprocess air cooler 303, then the low pressure section 220B of therefrigerant condenser 220 to the high pressure section 220A, thenthrough the desiccant wheel 103 and blower 140, therefore the passage ofregeneration air B proceeds downwardly from the top to the bottomthroughout the route. In the condensing section 252 of the process aircooler 303, it passes through from the low pressure section 303B to thehigh pressure section 303A. The heat-exchange between refrigerant andregeneration air B and between refrigerant and process air, is performedonly in the process air cooler 303, refrigerant condenser 220, andrefrigerant evaporator 210, so that for example, regeneration air Bflowing through the passage 129 from the blower 140, is thermallyseparated from refrigerant flowing into and out from the compressors260A, 260B.

In the embodiment shown in FIG. 42, like the embodiment shown in FIG.39, the blowers 102, 140 and compressor 260 are disposed below thedesiccant wheel 103, and the refrigerant condenser 220 and refrigerantevaporator 210 are disposed above the desiccant wheel 103. Therefrigerant condenser 220, process air cooler 303, and refrigerantevaporator 210 are disposed from the lower position to the upperposition in this order.

The embodiment shown in FIG. 42 is the same as described in theembodiment shown in FIG. 41 in that the refrigerant air passage proceedsupwardly from the blower 120 to the discharge port 106, and that theregeneration air passage proceeds downwardly until it reaches the blower140 after passing through the intake port 141, and then upwardly untilit reaches the discharge port 142 after exiting the blower 140horizontally and changing the direction by 90 degrees. Further, thisembodiment is the same as in the embodiment in FIG. 41 in that theintake port 104 of process air A is disposed in the vicinity of thebottom of the cabinet 700 (actually on one side thereof at the lowerportion), and the discharge port 106 of process air A is disposed on thetop of the cabinet 700; and that the intake port 141 of regeneration airB is disposed on the top of the cabinet 700, and the discharge port 142of regeneration air B is disposed on the top of the cabinet 700.

Next, referring to FIG. 43, the arrangement of devices of dehumidifyingair conditioner, which is another embodiment according to the presentinvention will be described below. In comparison with the embodimentsshown in FIGS. 39 and 42, only dissimilar features will be described andsimilar ones will not be repeated. This structure is preferable for thedehumidifying air conditioner described, referring to FIG. 33.

In the embodiment of a dehumidifying air conditioner shown in FIG. 43, aprocess air cooler 303 as a second is divided into a high pressure part303A which is located vertically on the lower side and a low pressurepart 303B which is located vertically on the upper side. Four heatexchanging tubes extending in horizontal direction are mountedvertically on the process air cooler 303. Each heat exchanging tube hasone throttle opening at the respective inlet and outlet of the processair cooler. Two of the four heat exchanging tubes are disposed on thelow pressure part 303B and the other two heat exchanging tubes aredisposed on the high pressure part 303A.

Evaporating section 251 of the process air cooler 303 contains a highpressure cycle heat exchanging tube for the high pressure part, a highpressure cycle heat exchanging tube for the low pressure part, a lowpressure cycle heat exchanging tube for the high pressure part and a lowpressure cycle heat exchanging tube for the low pressure part which aredisposed vertically in this order. Operating temperatures decrease alsoin this order.

On the other hand, condensing section 252 of the process air cooler 303contains a high pressure cycle heat exchanging tube for the highpressure part, a high pressure cycle heat exchanging tube for the lowpressure part, a low pressure cycle heat exchanging tube for the highpressure part, and allow pressure cycle heat exchanging tube for thehigh pressure part which are disposed vertically in this order. Throttleopening diameter is set such that operating temperature can decrease inthis order. If the operating temperatures of the heat exchanging tubesare set in this manner, a refrigerant condenser, a process air coolerand a refrigerant evaporator can maintain a high heat exchangeefficiency. Additionally, the process air cooler 303 exchanges heat withthe process air A and the regeneration air B, i.e., the process air A iscooled in the evaporating section 251 while the regeneration air B isheated in the condensing section 252.

In the embodiment shown in FIG. 43, in the same manner as shown in FIG.39, a blower 102, a blower 140 and compressors 260A, 260B are disposedvertically below the desiccant wheel, while a refrigerant condenser 220and a refrigerant evaporator 210 are disposed vertically above thedesiccant wheel. The refrigerant condenser 220, the process air cooler303 and the refrigerant evaporator 210 are also disposed verticallyupward in this order.

Additionally, in the embodiment shown in FIG. 43, it is the same withthe embodiment shown in FIG. 41 in that the passage for the process airextends vertically upward from the blower 102 to the discharge port 106,that the passage for the regeneration air extends vertically downwardfrom the intake port 141 to the blower 140, and extends verticallyupward to the discharge port 142, after extending from the blower 140and then bent at a right angle. Furthermore, it is also the same withthe embodiment shown in FIG. 41 in that the intake port 104 for theprocess air A is disposed near the bottom face of cabinet 700 (actuallyin the lower side face), that the discharge port 106 of the regenerationair A is disposed on the top face of the cabinet 700, that the intakeport 141 of the regeneration air B is disposed on the top face of thecabinet 700, and that the discharge port 142 of the regeneration air Bis disposed on the top face of the cabinet 700.

Next, referring to FIG. 44, the arrangement of the devices ofdehumidifying air conditioner, which is another embodiment will bedescribed below. In comparison with the embodiments shown in FIGS. 39and 41, only dissimilar features are described and similar ones are notrepeated. This structure is preferable for the dehumidifying airconditioner described, referring to FIG. 26.

In the embodiment of dehumidifying air conditioner shown in FIG. 44,refrigerant path in the refrigerant condenser 220 is made to branch outon the way and the refrigerant is taken out from the refrigerantcondenser 220. The heat exchanger 270 exchanges heat between therefrigerant taken out and the refrigerant flowing into the compressor260 from refrigerant evaporator 210, and the former refrigerant isjoined, at the header 235, with the refrigerant immediately beforeflowing into the process air cooler 303 as the second heat exchanger.

In the heat exchanger 270, refrigerant flowing into the compressor 260is heated with saturated steam of the refrigerant which has beencompressed. The refrigerant which has been compressed and raised intemperature is condensed in the refrigerant condenser 220 and exchangesheat with the regeneration air B (secondary heating of the regenerationair). The refrigerant is then evaporated in the evaporating section 251of the process air cooler 303, undergoes heat exchange with the processair A (cooling of the process air), and additionally condensed in thecondensing section 252 to exchange heat with the regeneration air B(primary heating of the regeneration air). The regeneration air B thushas a temperature high enough to regenerate the desiccant, which willresult in the desiccant having a higher dehumidifying capacity.

As described above, the regeneration air B is primarily heated at thecondensing section 252 of the process air cooler 303 and thensecondarily heated in the refrigerant condenser 220 before regeneratingthe desiccant.

Additionally, the process air cooler 303 exchanges heat throughrefrigerant, with the process air A and regeneration air B, and theprocess air A is cooled at the evaporating section 251, while theregeneration air B is heated in the condensing section 252.

The embodiment shown in FIG. 44 is the same with the embodiment shown inFIG. 39 in that a blower 102, a blower 140 and a compressor 260 aredisposed vertically below the desiccant wheel 103, while a refrigerantcondenser 220 and a refrigerant evaporator 210 are disposed above thedesiccant wheel 103. The refrigerant condenser 220, the process aircooler 303 and the refrigerant evaporator 210 are disposed verticallyupward in this order.

Furthermore, the embodiment shown in FIG. 44 is the same with theembodiment shown in FIG. 41 in that the passage for the process airextends vertically upward from the blower 102 to the discharge port 106,that the passage for the regeneration air extends vertically downwardfrom the intake port 141 to the blower 140, and extends verticallyupward to the discharge port 142, after extending from the blower 140and then bent at right angle. Furthermore, it is also the same with theembodiment shown in FIG. 41 in that the intake port 104 for the processair A is disposed near the bottom face of cabinet 700 (actually in thelower side face), that the discharge port 106 of the regeneration air Ais disposed on the top face of the cabinet 700, that the intake port 141of the regeneration air B is disposed on the top face of the cabinet700, and that the discharge port 142 of the regeneration air B isdisposed on the top face of the cabinet 700.

Next, referring to FIG. 45, the arrangement of the devices ofdehumidifying air conditioner, which is another embodiment will bedescribed below. In comparison with the embodiments shown in FIGS. 39and 44, only dissimilar features are described and similar ones are notrepeated.

In the embodiment of dehumidifying air conditioner shown in FIG. 45,refrigerant path in the refrigerant condenser 220 is made to branch outon the way and the refrigerant is taken out from the refrigerantcondenser 220. The heat exchanger 270 exchanges heat between therefrigerant taken out and the refrigerant flowing into the compressor260 from refrigerant evaporator 210. The former refrigerant then passesthrough a throttle 275 and is joined, at the upstream side of theexpansion valve 250 located immediately before the refrigerantevaporator 210. This structure is preferable for the dehumidifying airconditioner described, referring to FIG. 27.

In the heat exchanger 270, refrigerant flowing into the compressor 260is heated with saturated steam of the refrigerant which has beencompressed. The refrigerant which has been compressed to be raised intemperature is condensed in the refrigerant condenser 220 and exchangesheat with the regeneration air B (secondary heating of the regenerationair). The refrigerant is then evaporated in the evaporating section 251of the process air cooler 303 as the second heat exchanger, undergoesheat exchange with the process air A (cooling of the process air), andadditionally condensed in the condensing section 252 to exchange heatwith the regeneration air B (primary heating of the regeneration air).The regeneration air B thus has a temperature high enough to regeneratedesiccant, which will result in the desiccant having a higherdehumidifying capacity. As described above, the regeneration air B isprimarily heated at the condensing section 252 of the process air cooler303 and then secondarily heated in the refrigerant condenser 220 beforeregenerating desiccant.

Additionally, the process air cooler 303 exchanges heat throughrefrigerant, with the process air A and regeneration air B, and theprocess air A is cooled at the evaporating section 251, while theregeneration air B is heated in the condensing section 252.

The embodiment shown in FIG. 45 is the same with the embodiment shown inFIG. 39 in that a blower 102, a blower 140 and a compressor 260 aredisposed vertically below the desiccant wheel 103, while a refrigerantcondenser 220 and a refrigerant evaporator 210 are disposed above thedesiccant wheel 103. The refrigerant condenser 220, the process aircooler 303-and the refrigerant evaporator 210 are disposed verticallyupward in this order.

Furthermore, the embodiment shown in FIG. 44 is the same with theembodiment shown in FIG. 41 in that the passage for the process airextends vertically upward from the blower 102 to the discharge port 106,that the passage for the regeneration air extends vertically downwardfrom the intake port 141 to the blower 140, and extends verticallyupward to the discharge port 142, after extending from the blower 140and then bent at a right angle. Furthermore, it is also the same withthe embodiment shown in FIG. 41 in that the intake port 104 for theprocess air A is disposed near the bottom face of cabinet 700 (actuallyin the lower side face), that the discharge port 106 of the regenerationair A is disposed on the top face of the cabinet 700, that the intakeport 141 of the regeneration air B is disposed on the top face of thecabinet 700, and that the discharge port 142 of the regeneration air Bis disposed on the top face of the cabinet 700.

Next, referring to FIGS. 46, 47 and 48, the arrangement of the devicesof dehumidifying air conditioner, which is an embodiment will bedescribed below. FIG. 46 is a drawing omitting the blower 140 for theregeneration air from the FIG. 47. FIG. 48 is a side view in the left ofFIGS. 46 and 47.

The process air A is drawn by the blower 102 through the intake port 104fitted to the side face near the bottom face of the cabinet 700 and thensent vertically upward through the passage. The process air A passesvertically upward through one half (semicircle) of the desiccant wheel103, the axis of rotation of which is disposed vertically, and thedesiccant adsorbs moisture. The process air A, which passed thedesiccant wheel 103, flows vertically upward through the passage 109,then changes its direction by 90° and horizontally passes through theprocess air cooler 302 as the third heat exchanger which is disposed toextend vertically, while being cooled by the cooling air. The processair A further flows through the passage 110 sloped upward, thenhorizontally passes through the refrigerant evaporator 210 which isvertically disposed, and flows into the discharge port 106 provided nearthe top face of the side face opposite to the side having the intakeport 104 in the cabinet.

The regeneration air B is horizontally drawn through the intake port 141that is provided on the side face near the bottom face of the cabinet700. The regeneration air B, which was raised in pressure the blower140, flows aslant and upward through the passage 124 and then passthrough the heat exchanger 121 for exchanging heat with the regenerationair B heated by the refrigerant condenser 220. After flowing into thepassage 126, the regeneration air B changes its direction to flowvertically upward and passes through the refrigerant condenser 220 thatis disposed to extend vertically upward, while changing its direction by180° around there. After leaving the refrigerant condenser 220, theregeneration air B flows vertically downward through the passage 127,and then reaches and passes through, the heat exchanger 121 whilechanging its direction to flow aslant and downward. After leaving theheat exchanger 121, it changes its direction to pass horizontallythrough the passage 129 and then flow horizontally through the dischargeport 142 which is disposed on the side face near the bottom face of thecabinet 700.

On the top face of the cabinet 700 is provided a vertical type blower160 that can draw the cooling air. The blower 160 is shielded by hood163. An intake port which is located horizontally and laterally withrespect to the blower 150, is the intake port 166 of the device. Thecooling air flows vertically downward and passes through the process aircooler 302 while cooling the process air. Immediately after leaving theprocess air cooler 302, the cooling air, after changing its direction by90°, flows horizontally through the passage 172 and then flowhorizontally through the discharge port 172 which is disposed at aposition third of the full height from the uppermost side face of thecabinet 700.

The flow of refrigerant (not shown in FIGS. 46-47 though) cools theprocess air viathe refrigerant evaporator 210. Evaporated refrigerant iscompressed by the compressor 260, condensed after heating theregeneration air via the refrigerant condenser 220 and returned to therefrigerant evaporator 210 for circulation.

In the embodiments of FIGS. 46-48, blowers 102, 140, a compressor 260and a heat exchanger 121 are disposed vertically below the desiccantwheel 103, while a refrigerant evaporator 210, a refrigerant condenser220 and a process air cooler 302 are disposed vertically above thedesiccant wheel 103.

Here, in the fluid passage portion, through which the process air Aflows vertically upward, are fluid passages 108 and passage 109. Asecond fluid passage portion, through which the regeneration air B flowsvertically downward, is a fluid passage 127, while a first fluid passageportion, through which it flows vertically upward, is a passage 126.

If the fluid passages for the process air A and regeneration air B arearranged as described above, the process air A and regeneration air Bpassing through the desiccant wheel 103 will not have to change itsdirection around there, and therefore flow smoothly. Furthermore, thecompressor 260 and blowers 102, 104 can be disposed on the bottom facewhile main devices can be arranged vertically upward. Thus the equipmentcan become compact and decrease the space for installation.

Main devices as described above may contain the compressor 260, blowers102, 140, refrigerant compressor 220, refrigerant evaporator 210,process air cooler 300, desiccant wheel 103 and so forth.

As described above, the embodiments of dehumidifying air conditioneraccording to the present invention contain a desiccant wheel, the axisof rotation of which is vertically disposed. The fluid passages for theregeneration air can be constructed such that they have a first passageportion for vertically downward flow and a second passage portion forvertically upward flow. Thus the flows of regeneration air through theequipment can be streamlined, so that they may flow mainly verticallydownward to upward. As a result, the regeneration air will not have tochange its direction around the desiccant wheel and the main devices canbe arranged vertically upward. In comparison with those humidifying airconditioners which have desiccant wheels, axis of rotation of which arehorizontally disposed, the equipment herein can become compact and willreduce the space needed for installing the equipment.

Furthermore, because the present invention contains a blower for theprocess air/blower for the regeneration air and compressor which aredisposed vertically below desiccant wheel, while having refrigerantcompressor which are disposed vertically above the desiccant wheel,space can be horizontally reduced and thus the space needed forinstalling the equipment can be reduced. Additionally the process aircan flow upward through the blower for the process air and desiccantwheel, as arranged in this order, while the regeneration air can flowdownward through refrigerant compressor, desiccant wheel and blower forthe regeneration air, as arranged in this order. Thus a compact and lesstall humidifying air conditioner will come realized.

Additionally, if the refrigerant evaporator is disposed vertically abovethe desiccant wheel, space will be more reduced horizontally and thusthe space needed for installing the equipment will be even more reduced.Allowing the process air to flow upward through the blower for theprocess air then the desiccant wheel is a smoother arrangement order.Allowing the regeneration air to flow downward through the refrigerantevaporator then the desiccant wheel is a smoother arrangement order.Thus a much more compact and much less tall humidifying air conditionerwill come realized.

As the process air blower, regeneration air blower, compressor anddesiccant wheel are disposed near the bottom face, the humidifying airconditioner will have a lower center of gravity. Additionally, becausethe process air blower, regeneration air blower and compressor arearranged at lower positions close to the foundation bolts of theequipment, the humidifying air conditioner will be less affected by anyvibration and have a greater stability during installation.

Industrial Applicability

As described above, the present invention allows the provision of a heatexchanger of a higher heat exchange efficiency, higher COP heat pump,higher COP dehumidifying air conditioner, and a more space-savingdehumidifying air conditioner.

What is claimed is:
 1. A heat exchanger comprising: a first compartmentfor a first fluid flowing therethrough; a second compartment for asecond fluid flowing therethrough; a first flow passage passing throughthe first compartment and for a third fluid flowing therethrough, thethird fluid exchanging heat with the first fluid; and a second flowpassage passing through the second compartment and for the third fluidflowing therethrough, the third fluid exchanging heat with the secondfluid; wherein the first and second flow passages are formed as anintegral passage; the third fluid flows through from the first flowpassage to the second flow passage, and the third fluid evaporates on aheat transfer surface located at a flow passage side of the first flowpassage at a specific pressure, the flow passage side being for thethird fluid flowing therein, and condenses on a heat transfer surfacelocated at a flow passage side of the second flow passage atapproximately the same pressure as the specific pressure, the flowpassage side being for the third fluid flowing therein.
 2. A heatexchanger as recited in claim 1, wherein the second fluid flowingthrough the second compartment is caused to contain water.
 3. A heatexchanger as recited in claim 1, further comprising a third flow passagepassing through the second compartment and disposed parallel to thesecond flow passage for the third fluid flowing threrethrough, the thirdfluid exchanging heat with the second fluid, wherein the third fluidsubstantially bypasses the first compartment and is supplied to thethird flow passage.
 4. A heat exchanger as recited in claim 3, whereinthe third fluid mainly in liquid phase is supplied to the first flowpassage, and the third fluid mainly in vapor phase is supplied to thethird flow passage.
 5. A heat exchanger comprising: a first compartmentfor a first fluid flowing therethrough; a second compartment for asecond fluid flowing therethrough; first flow passages passing throughthe first compartment and for a third fluid flowing therethrough, thethird fluid exchanging heat with the first fluid; and second flowpassages passing through the second compartment and for the third fluidflowing therethrough, the third fluid exchanging heat with the secondfluid; wherein the third fluid flows through from the first flow passageto the second flow passage, the third fluid evaporates on the heattransfer surfaces located on the flow passage side of the first flowpassages at specific pressures and condenses on the heat transfersurfaces located on the flow passage side of the second flow passages atapproximately the same pressures as the specific pressures; the firstflow passages are provided in a plurality; and the specific pressures inthe plurality of flow passages are different from each other.
 6. A heatpump comprising a heat exchanger including: a first compartment for afirst fluid flowing therethrough; a second compartment for a secondfluid flowing therethrough; a first flow passage passing through thefirst compartment and for a third fluid flowing therethrough, the thirdfluid exchanging heat with the first fluid; and a second flow passagepassing through the second compartment and for the third fluid flowingtherethrough, the third fluid exchanging heat with the second fluid;wherein the first and second flow passages are formed as an integralpassage; the third fluid flows through from the first flow passage tothe second flow passage, and the third fluid evaporates on a heattransfer surface located at a flow passage side of the first flowpassage at a specific pressure, the flow passage side being for thethird fluid flowing therein, and condenses on a heat transfer surfacelocated at a flow passage side of the second flow passage atapproximately the same pressure as the specific pressure, the flowpassage side being for the third fluid flowing therein; a pressureraiser for raising the pressure of the third fluid in vapor phase; afirst heat exchanger for taking heat from the third fluid in vaporphase, the third fluid in vapor phase having been boosted with thepressure raiser, with a high temperature fluid, thus causing the thirdfluid in vapor phase to condense under a first pressure; a firstthrottle for reducing the third fluid in pressure, the third fluidhaving been condensed with the first heat exchanger, to the specificpressure and for leading the third fluid to the first flow passage; asecond throttle for reducing the third fluid in pressure, the thirdfluid having been condensed at the specific pressure, to a thirdpressure; and a third heat exchanger for evaporating the third fluid,the third fluid having been reduced in pressure with the secondthrottle, by imparting heat to the third fluid from a low temperaturefluid under the third pressure.
 7. A heat pump comprising a heatexchanger including: a first compartment for a first fluid flowingtherethrough; a second compartment for a second fluid flowingtherethrough; a first flow passage passing through the first compartmentand for a third fluid flowing therethrough, the third fluid exchangingheat with the first fluid; and a second flow passage passing through thesecond compartment and for the third fluid flowing therethrough, thethird fluid exchanging heat with the second fluid; wherein the first andsecond flow passages are formed as an integral passage; the third fluidflows through from the first flow passage to the second flow passage,and the third fluid evaporates on a heat transfer surface located at aflow passage side of the first flow passage at a specific pressure, theflow passage side being for the third fluid flowing therein, andcondenses on a heat transfer surface located at a flow passage side ofthe second flow passage at approximately the same pressure as thespecific pressure, the flow passage side being for the third fluidflowing therein a compressor for compressing the pressure of the thirdfluid in vapor phase; a first heat exchanger for taking heat from thethird fluid in vapor phase, the third fluid in vapor phase having beencompressed with the compressor, with a high temperature fluid, thuscausing the third fluid in vapor phase to condense under a firstpressure; a first throttle for reducing the third fluid in pressure, thethird fluid having been condensed with the first heat exchanger, to thespecific pressure and for leading the third fluid to the first flowpassage; a second throttle for reducing the third fluid in pressure, thethird fluid having been condensed at the specific pressure, to a thirdpressure; and a third heat exchanger for evaporating the third fluid,the third fluid having been reduced in pressure with the secondthrottle, by imparting heat to the third fluid from a low temperaturefluid under the third pressure.
 8. A dehumidifier comprising; the heatpump as recited in claim 7; and a moisture adsorber having a desiccantfor adsorbing moisture in the first fluid; wherein the heat exchanger isdisposed on the downstream side of the first fluid flow relative to themoisture adsorber, so as to cool the first fluid from which moisture isadsorbed by the desiccant.
 9. A heat pump comprising; a pressure raiserfor raising the pressure of a refrigerant; a first heat exchanger forcondensing the refrigerant, the refrigerant having been boosted with thepressure raiser, by taking heat from the refrigerant with a hightemperature fluid under a first pressure; a first throttle for reducingthe refrigerant in pressure, the refrigerant having been condensed withthe first heat exchanger, to a second pressure; a second heat exchangerfor evaporating the refrigerant, the refrigerant having been reduced inpressure with the first throttle, by the heat from the first fluid underthe second pressure, and for condensing the refrigerant, after theevaporation, by taking heat from the refrigerant with a second fluid; asecond throttle for reducing the refrigerant in pressure, after beingcondensed with the second heat exchanger, to a third pressure; and athird heat exchanger for evaporating the refrigerant, the refrigeranthaving been reduced in pressure with the second throttle, by impartingheat to the refrigerant from low temperature fluid under the thirdpressure.
 10. A heat pump comprising; a compressor for compressing arefrigerant; a first heat exchanger for condensing the refrigerant, therefrigerant having been compressed with the compressor, by taking heatfrom the refrigerant with a high temperature fluid under a firstpressure; a first throttle for reducing the refrigerant in pressure, therefrigerant having been condensed with the first heat exchanger, to asecond pressure; a second heat exchanger for evaporating therefrigerant, the refrigerant having been reduced in pressure with thefirst throttle, by the heat from the first fluid under the secondpressure, and for condensing the refrigerant, after the evaporation, bytaking heat from the refrigerant with a second fluid; a second throttlefor reducing the refrigerant in pressure, after being condensed with thesecond heat exchanger, to a third pressure; and a third heat exchangerfor evaporating the refrigerant, the refrigerant having been reduced inpressure with the second throttle, by imparting heat to the refrigerantfrom low temperature fluid under the third pressure.
 11. A heat pump asrecited in claim 10: wherein the second heat exchanger comprises; afirst compartment for the first fluid flowing therethrough, a secondcompartment for the second fluid flowing therethrough, a first flowpassage passing through the first compartment and for the refrigerantflowing therethrough, the refrigerant exchanging heat with the firstfluid, and a second flow passage passing through the second compartmentand for the refrigerant flowing therethrough, the refrigerant exchangingheat with the second fluid; wherein the refrigerant flows through fromthe first flow passage to the second flow passage, the refrigerantevaporates under the second pressure on the heat transfer surfacelocated on the flow passage side of the first flow passage, andcondenses approximately under the second pressure on the heat transfersurface located on the flow passage side of the second flow passage. 12.A heat pump as recited in claim 10, comprising: a vapor-liquid separatordisposed between the first throttle and the second heat exchanger so asto separate the refrigerant, that has been reduced in pressure to thesecond pressure, into refrigerant liquid and refrigerant vapor.
 13. Aheat pump as recited in claim 11, comprising: a vapor-liquid separatordisposed between the first throttle and the second heat exchanger so asto separate the refrigerant, the refrigerant having been reduced inpressure to the second pressure, into refrigerant liquid and refrigerantvapor; and a third flow passage disposed parallel to the second flowpassage; wherein the refrigerant liquid separated with the vapor-liquidseparator is caused to flow to the first flow passage, and therefrigerant vapor separated with the vapor-liquid separator is caused tobypass the first flow passage and to flow to the third flow passage. 14.A heat pump as recited in claim 10: wherein the second heat exchangercomprises; a first compartment for the first fluid flowing therethrough;a second compartment for the second fluid flowing therethrough; firstflow passages passing through the first compartment and for therefrigerant flowing therethrough, the refrigerant exchanging heat withthe first fluid; and second flow passages passing through the secondcompartment and for the refrigerant flowing therethrough, therefrigerant exchanging heat with the second fluid; wherein therefrigerant flows through from the first flow passages to the secondflow passages; the refrigerant evaporates under the second pressure onthe heat transfer surfaces located on the flow passage side of the firstflow passages, and condenses approximately under the second pressure onthe heat transfer surfaces located on the flow passage side of thesecond flow passages; the first flow passages are provided in aplurality; and the second pressures in the plurality of flow passagesare different from each other.
 15. A dehumidifier comprising: the heatpump as recited in claim 10; and a moisture adsorber having a desiccantfor adsorbing moisture in the low temperature fluid; wherein the secondheat exchanger is disposed on the downstream side of the low temperaturefluid flow relative to the moisture adsorber, so as to cool the lowtemperature fluid, from which moisture has been adsorbed with thedesiccant, and before low temperature fluid causes the refrigerant toevaporate with the third heat exchanger.
 16. A dehumidifier comprising:a moisture adsorber having a desiccant for adsorbing moisture in theprocess air; and a process air cooler, disposed on the downstream sideof the process air flow relative to the moisture adsorber, for coolingthe process air from which moisture has been adsorbed with thedesiccant; wherein the process air cooler cools the process air by theevaporation of a refrigerant, the evaporation being at a specificpressure, wherein all of the refrigerant is forced to flow generally inone direction and the process air cooler condenses the evaporatedrefrigerant at approximately the same pressure as the specific pressurein the process air cooler, cooled with a cooling fluid.
 17. A method ofdehumidifying process air, comprising: a first step of cooling theprocess air with a refrigerant that evaporates at a low pressure; asecond step of raising the pressure of the refrigerant, that hasevaporated in the first step, to a high pressure; a third step ofheating regeneration air for regenerating a desiccant with therefrigerant that condenses at the high pressure; a fourth step ofregenerating the desiccant by desorbing moisture from the desiccant withthe regeneration air heated in the third step; a fifth step of adsorbingmoisture in the process air with the desiccant regenerated in the fourthstep; a sixth step of cooling the process air, from which moisture hasbeen removed by adsorption in the fifth step, by evaporating therefrigerant, that has condensed in the third step, at an intermediatepressure between the low pressure and the high pressure; and a seventhstep of condensing the refrigerant, that has evaporated at theintermediate pressure, at a pressure which is approximately the same asthe intermediate pressure.
 18. A dehumidifier comprising: a firstrefrigerant-air heat exchanger having a first refrigerant inlet-outletport and a second refrigerant inlet-outlet port, and for causing heatexchange between a refrigerant and a process air; a compressor having anintake port and a discharge port for taking in and discharging therefrigerant, with the second refrigerant inlet-outlet port beingdisposed to be selectively connectable to either the intake port or thedischarge port; a second refrigerant-air heat exchanger having a thirdrefrigerant inlet-outlet port and a fourth refrigerant inlet-outletport, and for causing heat exchange between the refrigerant and theprocess air, with either the intake port or the discharge port, that hasnot been connected to the second refrigerant inlet-outlet port, beingdisposed to be connectable to the third refrigerant inlet-outlet port; athird refrigerant-air heat exchanger, disposed on the upstream side ofthe process air flow flowing through the first refrigerant-air heatexchanger, having a fifth refrigerant inlet-outlet port and a sixthrefrigerant inlet-outlet port, and for causing heat exchange among therefrigerant, the process air, and a cooling fluid, with the fourthrefrigerant inlet-outlet port being disposed to be selectivelyconnectable to either the fifth refrigerant inlet-outlet port or a sixthrefrigerant inlet-outlet port, and a moisture adsorber disposed on theupstream side of the process air flow passing through the thirdrefrigerant-air heat exchanger and having a desiccant for adsorbingmoisture in the process air, wherein: either the fifth refrigerantinlet-outlet port or the sixth refrigerant inlet-outlet port that hasnot been connected to the fourth refrigerant inlet-outlet port isconnected to the first refrigerant inlet-outlet port, and the thirdrefrigerant-air heat exchanger cools the process air passing through thethird refrigerant-air heat exchanger by the evaporation of therefrigerant supplied from the fourth refrigerant inlet-outlet port tothe fifth refrigerant inlet-outlet port when the fourth refrigerantinlet-outlet port and the fifth refrigerant inlet-outlet port areinterconnected, and cools and condenses the evaporated refrigerant withthe cooling fluid, so that the condensed refrigerant can be supplied tothe first refrigerant-air heat exchanger.
 19. A dehumidifier as recitedin claim 18, further comprising: a first switching mechanism forswitching the selective connecting relation of the intake and dischargeports of the compressor to the second and the third refrigerantinlet-outlet ports; and a second switching mechanism for switching theselective connecting relation of the fifth and the sixth refrigerantinlet-outlet ports to the fourth and the first refrigerant inlet-outletports.
 20. A dehumidifier comprising: a first refrigerant-air heatexchanger having a first refrigerant inlet-outlet port and a secondrefrigerant inlet-outlet port, and for causing heat exchange between arefrigerant and a process air; a compressor having an intake port and adischarge port for taking in and discharging the refrigerant, with thesecond refrigerant inlet-outlet port being disposed to be selectivelyconnectable to either the intake port or the discharge port; a secondrefrigerant-air heat exchanger having a third refrigerant inlet-outletport and a fourth refrigerant inlet-outlet port, and for causing heatexchange between the refrigerant and the process air, with either theintake port or the discharge port, that has not been connected to thesecond refrigerant inlet-outlet port, being disposed to be connectableto the third refrigerant inlet-outlet port; a third refrigerant-air heatexchanger, disposed on the upstream side of the process air flow flowingthrough the first refrigerant-air heat exchanger, having a fifthrefrigerant inlet-outlet port and a sixth refrigerant inlet-outlet port,and for causing heat exchange among the refrigerant, the process air,and a cooling fluid, with the fourth refrigerant inlet-outlet port beingdisposed to be selectively connectable to either the fifth refrigerantinlet-outlet port or a sixth refrigerant inlet-outlet port, and amoisture adsorber disposed on the upstream side of the process air flowpassing through the third refrigerant-air heat exchanger and having adesiccant for adsorbing moisture in the process air, wherein: either thefifth refrigerant inlet-outlet port or the sixth refrigerantinlet-outlet port that has not been connected to the fourth refrigerantinlet-outlet port is connected to the first refrigerant inlet-outletport, the third refrigerant-air heat exchanger cools the process airpassing through the third refrigerant-air heat exchanger by theevaporation of the refrigerant supplied from the fourth refrigerantinlet-outlet port to the fifth refrigerant inlet-outlet port when thefourth refrigerant inlet-outlet port and the fifth refrigerantinlet-outlet port are interconnected, and cools and condenses theevaporated refrigerant with the cooling fluid, so that the condensedrefrigerant can be supplied to the first refrigerant-air heat exchangera first switching mechanism for switching the selective connectingrelation of the intake and discharge ports of the compressor to thesecond and the third refrigerant inlet-outlet ports; a second switchingmechanism for switching the selective connecting relation of the fifthand the sixth refrigerant inlet-outlet ports to the fourth and the firstrefrigerant inlet-outlet ports an expansion valve disposed in therefrigerant passage between the sixth refrigerant inlet-outlet port andthe second switching mechanism, the expansion valve having a firsttemperature sensor and a second temperature sensor, wherein the firsttemperature sensor is disposed in the refrigerant passage between thesecond refrigerant inlet-outlet port and the first switching mechanism,and the second temperature sensor is disposed in the refrigerant passagebetween the first switching mechanism and the third refrigerantinlet-outlet port, and the first and the second temperature sensors canbe selectively switched.
 21. A dehumidifier as recited in claim 18;wherein the regeneration air is passed through the secondrefrigerant-air heat exchanger and the moisture adsorber, the desiccantbeing regenerated with the regeneration air, is disposed on thedownstream side of the regeneration air flow relative to the secondrefrigerant-air heat exchanger; and further comprising: a sensible heatexchanger, disposed on the upstream side of the regeneration airrelative to the second refrigerant-air heat exchanger, for causing heatexchange between the regeneration air that has passed through themoisture adsorber and the regeneration air before exchanging heat in thesecond refrigerant-air heat exchanger; and a switching mechanism forswitching the sensible heat exchanger between operative and inoperativestates.
 22. A dehumidifier comprising: a first refrigerant-air heatexchanger having a first refrigerant inlet-outlet port and a secondrefrigerant inlet-outlet port, and for causing heat exchange between arefrigerant and a process air; a compressor having an intake port and adischarge port for taking in and discharging the refrigerant, with thesecond refrigerant inlet-outlet port being disposed to be selectivelyconnectable to either the intake port or the discharge port; a secondrefrigerant-air heat exchanger having a third refrigerant inlet-outletport and a fourth refrigerant inlet-outlet port, and for causing heatexchange between the refrigerant and the process air, with either theintake port or the discharge port, that has not been connected to thesecond refrigerant inlet-outlet port, being disposed to be connectableto the third refrigerant inlet-outlet port; a third refrigerant-air heatexchanger, disposed on the upstream side of the process air flow flowingthrough the first refrigerant-air heat exchanger, having a fifthrefrigerant inlet-outlet port and a sixth refrigerant inlet-outlet port,and for causing heat exchange among the refrigerant, the process air,and a cooling fluid, with the fourth refrigerant inlet-outlet port beingdisposed to be selectively connectable to either the fifth refrigerantinlet-outlet port or a sixth refrigerant inlet-outlet port, and amoisture adsorber disposed on the upstream side of the process air flowpassing through the third refrigerant-air heat exchanger and having adesiccant for adsorbing moisture in the process air, wherein: either thefifth refrigerant inlet-outlet port or the sixth refrigerantinlet-outlet port that has not been connected to the fourth refrigerantinlet-outlet port is connected to the first refrigerant inlet-outletport, the third refrigerant-air heat exchanger cools the process airpassing through the third refrigerant-air heat exchanger by theevaporation of the refrigerant supplied from the fourth refrigerantinlet-outlet port to the fifth refrigerant inlet-outlet port when thefourth refrigerant inlet-outlet port and the fifth refrigerantinlet-outlet port are interconnected, and cools and condenses theevaporated refrigerant with the cooling fluid, so that the condensedrefrigerant can be supplied to the first refrigerant-air heat exchanger,wherein air is used as the cooling fluid, and liquid state water issupplied together with the air before condensing the refrigerant in thethird refrigerant-air heat exchanger.
 23. An operation method of adehumidifier including a first refrigerant-air heat exchanger having afirst refrigerant inlet-outlet port and a second refrigerantinlet-outlet port, and for causing heat exchange between a refrigerantand a process air; a compressor having an intake port and a dischargeport for taking in and discharging the refrigerant, with the secondrefrigerant inlet-outlet port being disposed to be selectivelyconnectable to either the intake port or the discharge port; a secondrefrigerant-air heat exchanger having a third refrigerant inlet-outletport and a fourth refrigerant inlet-outlet port, and for causing heatexchange between the refrigerant and the process air, with either theintake port or the discharge port, that has not been connected to thesecond refrigerant inlet-outlet port, being disposed to be connectableto the third refrigerant inlet-outlet port; a third refrigerant-air heatexchanger, disposed on the upstream side of the process air flow flowingthrough the first refrigerant-air heat exchanger, having a fifthrefrigerant inlet-outlet port and a sixth refrigerant inlet-outlet port,and for causing heat exchange among the refrigerant, the process air,and a cooling fluid, with the fourth refrigerant inlet-outlet port beingdisposed to be selectively connectable to either the fifth refrigerantinlet-outlet port or a sixth refrigerant inlet-outlet port, and amoisture adsorber disposed on the upstream side of the process air flowpassing through the third refrigerant-air heat exchanger and having adesiccant for adsorbing moisture in the process air, wherein: either thefifth refrigerant inlet-outlet port or the sixth refrigerantinlet-outlet port that has not been connected to the fourth refrigerantinlet-outlet port is connected to the first refrigerant inlet-outletport, the third refrigerant-air heat exchanger cools the process airpassing through the third refrigerant-air heat exchanger by theevaporation of the refrigerant supplied from the fourth refrigerantinlet-outlet port to the fifth refrigerant inlet-outlet port when thefourth refrigerant inlet-outlet outlet port and the fifth refrigerantinlet-outlet port are interconnected, and cools and condenses theevaporated refrigerant with the cooling fluid, so that the condensedrefrigerant can be supplied to the first refrigerant-air heat exchanger,said method comprising the steps of: interconnecting, in the coolingoperation mode, the second refrigerant inlet-outlet port and the intakeport, the discharge port and the third refrigerant inlet-outlet port,the fourth refrigerant inlet-outlet port and the fifth refrigerantinlet-outlet port, and the sixth refrigerant inlet-outlet port and thefirst refrigerant inlet-outlet port, respectively; interconnecting, inthe heating mode, the second refrigerant inlet-outlet port and thedischarge port, the intake port and the third refrigerant inlet-outletport, the fourth refrigerant inlet-outlet port and the sixth refrigerantinlet-outlet port, and the fifth refrigerant inlet-outlet port and thefirst refrigerant inlet-outlet port, respectively; and setting the thirdrefrigerant-air heat exchanger at inoperative state.
 24. An operationmethod as recited in claim 23, further comprising a step ofinterconnecting, in the defrosting mode, the second refrigerantinlet-outlet port and the intake port, the discharge port and the thirdrefrigerant inlet-outlet port, the fourth refrigerant inlet-outlet portand the sixth refrigerant inlet-outlet port, and the fifth refrigerantinlet-outlet port and the first refrigerant inlet-outlet port,respectively.
 25. A dehumidifier comprising: a moisture adsorber havinga desiccant for adsorbing moisture in the process air; and a process aircooler for cooling the process air from which moisture has been removedby adsorption with the desiccant; wherein the process air cooler has aconstruction of cooling the process air by the evaporation of therefrigerant, and the evaporated refrigerant is cooled and condensed witha cooling fluid at substantially the same pressure as the evaporatingpressure; and the process air cooler has a plurality of evaporationpressures of the refrigerant for cooling the process air and a pluralityof condensation pressures of the refrigerant cooled and condensed withthe cooling fluid corresponding to the evaporation pressures, theplurality of evaporation pressures being different from each other. 26.A dehumidifier as recited in claim 25, comprising: an evaporator forfurther cooling the process air, the process air having been cooled withthe process air cooler, by evaporating the refrigerant condensed withthe process air cooler; a compressor for compressing the refrigerantvaporized by evaporation with the evaporator; and a condenser forcooling and condensing the refrigerant, the refrigerant having beencompressed with the compressor, with the regeneration air; wherein, therefrigerant having been condensed with the condenser is supplied to theprocess air cooler.
 27. A dehumidifier as recited in claim 25: whereinair is used as the cooling fluid, and the air, after having condensedthe refrigerant in the process air cooler, is led as the regenerationair for regenerating the desiccant, to the moisture adsorber.
 28. Adehumidifier comprising: a moisture adsorber having a desiccantadsorbing moisture from the process air and being regenerated with theregeneration air; a heat pump, having a compressor for compressing arefrigerant, for pumping up heat from a low temperature heat source to ahigh temperature heat source using the process air as the lowtemperature heat source and the regeneration air as the high temperatureheat source; and a process air cooler, disposed on the downstream sideof the process air flow relative to the moisture adsorber, for coolingthe process air from which moisture has been removed by adsorption withthe desiccant; wherein the refrigerant before being taken into thecompressor is heated by the refrigerant after being compressed with thecompressor subsequently exchanging heat with the regeneration air beforeregenerating the desiccant, and the process air cooler has aconstruction of cooling the process air by the evaporation of therefrigerant, and of cooling to condense the refrigerant with a coolingfluid at substantially the same pressure as the evaporating pressure.29. A dehumidifier as recited in claim 28, comprising: an evaporator forfurther cooling the process air, the process air having been cooled withthe process air cooler, by evaporating the refrigerant, the refrigeranthaving been condensed with the process air cooler; and a condenser forcooling to condense the refrigerant, the refrigerant having beencompressed with the compressor; wherein the refrigerant having beencondensed with the condenser is supplied to the process air cooler. 30.A dehumidifier as recited in claim 29, wherein the regeneration air,before flowing into the condenser, is used as the cooling fluid.
 31. Adehumidifier comprising: a moisture adsorber having a desiccantadsorbing moisture from the process air and being regenerated with theregeneration air; a heat pump, having a compressor for compressing arefrigerant, for pumping up heat from a low temperature heat source to ahigh temperature heat source using the process air as the lowtemperature heat source and the regeneration air as the high temperatureheat source; and a process air cooler, disposed on the downstream sideof the process air flow relative to the moisture adsorber, for coolingthe process air from which moisture has been removed by adsorption withthe desiccant; wherein the refrigerant before being taken into thecompressor is heated by the refrigerant after being compressed with thecompressor subsequently exchanging heat with the regeneration air beforeregenerating the desiccant, and the process air cooler has aconstruction of cooling the process air by the evaporation of therefrigerant, and of cooling to condense the refrigerant with a coolingfluid, wherein the process air cooler has a construction such that airis used as the cooling fluid, and liquid state water is suppliedtogether with the air.
 32. A dehumidifier comprising: a moistureadsorber having a desiccant for adsorbing moisture in process air, withthe adsorbed moisture being desorbed with regeneration air; a first heatpump for pumping up heat from a first evaporation temperature to a firstcondensation temperature by circulating a refrigerant, the first heatpump evaporating the refrigerant at a first intermediate temperaturebetween the first evaporation temperature and the first condensationtemperature, followed by condensing the refrigerant at a temperaturethat is approximately equal to the first intermediate temperature; and asecond heat pump for pumping up heat from a second evaporationtemperature which is lower than the first evaporation temperature to asecond condensation temperature which is lower than the firstcondensation temperature by circulating a refrigerant, the second heatpump evaporating the refrigerant at a second intermediate temperaturebetween the second evaporation temperature and the second condensationtemperature, followed by condensing the refrigerant at a temperaturethat is approximately equal to the second intermediate temperature;wherein the process air from which moisture has been removed byadsorption with the desiccant is first cooled with the refrigerant thatevaporates at either the first intermediate temperature or the secondintermediate temperature whichever higher, then cooled with therefrigerant that evaporates at the lower intermediate temperature, thencooled with the refrigerant that evaporates at the first evaporationtemperature, then cooled with the refrigerant that evaporates at thesecond evaporation temperature; the regeneration air is heated with therefrigerant that condenses at either a temperature that is approximatelyequal to the first intermediate temperature or a temperature that isapproximately equal to the second intermediate temperature, whichever islower, then heated with the refrigerant that condenses at the highertemperature, then heated with a refrigerant that condenses at the secondcondensation temperature, then heated with a refrigerant that condensesat the first condensation temperature, and then the moisture is removedfrom the desiccant by desorption with the heated regeneration air.
 33. Adehumidifier comprising: a moisture adsorber having a desiccant foradsorbing moisture in process air, the moisture being desorbed withregeneration air; a process air cooler, disposed on the downstream sideof the process air flow relative to the moisture adsorber, for coolingthe process air; a first condenser for heating the regeneration air bycondensing a refrigerant at a first condensing pressure; and a secondcondenser for heating the regeneration air by condensing a refrigerantat a second condensing pressure which is lower than the first condensingpressure; wherein the process air cooler has a construction of coolingthe process air by the evaporation of the refrigerant, and of cooling tocondense the evaporated refrigerant with the regeneration air beforeremoving moisture from the desiccant in the moisture adsorber; thesecond condenser and the first condenser are disposed in that order inthe passage from the regeneration air between the process air cooler andthe moisture adsorber; the process air cooler has, as evaporationpressures of the refrigerant for cooling the process air, a firstintermediate pressure which is lower than the first condensationpressure and a second intermediate pressure which is lower than thefirst intermediate pressure; the process air cooler has a constructionof cooling the refrigerant with the regeneration air to condense therefrigerant at approximately the first intermediate pressure and atapproximately the second intermediate pressure; the process air coolerhas a construction of cooling the process air with the refrigerant thatevaporates at the second intermediate pressure after the regenerationair is cooled with the refrigerant that evaporates at the firstevaporation pressure, and heating the regeneration air with therefrigerant that condenses approximately at the first intermediatepressure, after heating the regeneration air is heated with therefrigerant that condenses approximately at the second intermediatepressure; and the refrigerant condensed with the first condenser issupplied so as to be evaporated at either one of the first or the secondintermediate pressures, and the refrigerant condensed with the secondcondenser is supplied so as to be evaporated at the other one of thefirst or the second intermediate pressures.
 34. A dehumidifier asrecited in claim 33, further comprising: a first evaporator, disposed onthe downstream side of the process air coming from the process aircooler, for cooling the process air by evaporating the refrigerant at afirst evaporation pressure which is lower than the first intermediatepressure; a second evaporator, disposed on the downstream side of theprocess air coming from the first evaporator, for cooling the processair by evaporating the refrigerant at a second evaporation pressurewhich is lower than the first evaporation pressure; a first compressorfor compressing the refrigerant evaporated with the first evaporator andsending the refrigerant to the first condenser; and a second compressorfor compressing the refrigerant evaporated with the second evaporatorand supplying the refrigerant to the second condenser.
 35. A dehumdifiercomprising: a moisture adsorber having a desiccant for adsorbingmoisture in process air, the moisture being desorbed with regenerationair; a process air cooler, disposed on the downstream side of theprocess air flow relative to the moisture adsorber, for cooling theprocess air; a first condenser for heating the regeneration air bycondensing a refrigerant at a first condensing pressure; and a secondcondenser for heating the regeneration air by condensing a refrigerantat a second condensing pressure which is lower than the first condensingpressure; wherein the process air cooler has a construction of coolingthe process air by the evaporation of the refrigerant, and of cooling tocondense the evaporated refrigerant with the regeneration air beforeremoving moisture from the desiccant in the moisture adsorber; thesecond condenser and the first condenser are disposed in that order inthe passage from the regeneration air between the process air cooler andthe moisture adsorber; the process air cooler has, as evaporationpressures of the refrigerant for cooling the process air, a firstintermediate pressure which is lower than the first condensationpressure and a second intermediate pressure which is lower than thefirst intermediate pressure; the process air cooler has a constructionof cooling the refrigerant with the regeneration air to condense therefrigerant at approximately the first intermediate pressure and atapproximately the second intermediate pressure; the process air coolerhas a construction of cooling the process air with the refrigerant thatevaporates at the second intermediate pressure after the regenerationair is cooled with the refrigerant that evaporates at the firstevaporation pressure, and heating the regeneration air with therefrigerant that condenses approximately at the first intermediatepressure, after heating the regeneration air is heated with therefrigerant that condenses approximately at the second intermediatepressure; and the refrigerant condensed with the first condenser issupplied so as to be evaporated at either one of the first or the secondintermediate pressures, and the refrigerant condensed with the secondcondenser is supplied so as to be evaporated at the other one of thefirst or the second intermediate pressures, wherein the firstintermediate pressure further includes a plurality of pressures.
 36. Adehumidifier comprising a moisture adsorber having a desiccant foradsorbing moisture in process air, the moisture being desorbed withregeneration air; a process air cooler, disposed on the downstream sideof the process air flow relative to the moisture adsorber, for coolingthe process air; a first condenser for heating the regeneration air bycondensing a refrigerant at a first condensing pressure; and a secondcondenser for heating the regeneration air by condensing a refrigerantat a second condensing pressure which is lower than the first condensingpressure; wherein the process air cooler has a construction of coolingthe process air by the evaporation of the refrigerant, and of cooling tocondense the evaporated refrigerant with the regeneration air beforeremoving moisture from the desiccant in the moisture adsorber; thesecond condenser and the first condenser are disposed in that order inthe passage from the regeneration air between the process air cooler andthe moisture adsorber; the process air cooler has, as evaporationpressures of the refrigerant for cooling the process air, a firstintermediate pressure which is lower than the first condensationpressure and a second intermediate pressure which is lower than thefirst intermediate pressure; the process air cooler has a constructionof cooling the refrigerant with the regeneration air to condense therefrigerant at approximately the first intermediate pressure and atapproximately the second intermediate pressure; the process air coolerhas a construction of cooling the process air with the refrigerant thatevaporates at the second intermediate pressure after the regenerationair is cooled with the refrigerant that evaporates at the firstevaporation pressure, and heating the regeneration air with therefrigerant that condenses approximately at the first intermediatepressure, after heating the regeneration air is heated with therefrigerant that condenses approximately at the second intermediatepressure; and the refrigerant condensed with the first condenser issupplied so as to be evaporated at either one of the first or the secondintermediate pressures, and the refrigerant condensed with the secondcondenser is supplied so as to be evaporated at the other one of thefirst or the second intermediate pressures, wherein the first and thesecond condensers are positioned vertically above the process aircooler.
 37. A dehumidifier comprising a first air flow passage having afirst intake port at its one end and a first discharge port at the otherend, for flowing first air from the first intake port toward the firstdischarge port; a second air flow passage having a second intake port atits one end and a second discharge port at the other end, for flowingregeneration air from the second intake port toward the second dischargeport; a desiccant wheel, having a desiccant for the process air to passthrough, with its rotation axis directed vertically; and a third heatexchanger for cooling the process air, wherein the desiccant removesmoisture from the process air before being cooled by the third heatexchanger; and wherein the first air passage mainly includes a downwardflow passage portion directed vertically downward and an upward flowpassage portion directed vertically upward; and wherein moisture of thedesiccant is removed by the regeneration air, and the second air flowpassage mainly includes a flow passage portion directed verticallyupward.
 38. A dehumidifier as recited in claim 37, comprising: a firstheat exchanger for heating the regeneration air; and a heat pump havinga high temperature heat source and a low temperature heat source;wherein the third heat exchanger constitutes the low temperature heatsource, and the first heat exchanger constitutes the high temperatureheat source.
 39. A dehumidifier comprising: a process air blower forblowing process air; a regeneration air blower for blowing regenerationair; a compressor for compressing a refrigerant; a refrigerant condenserfor heating the regeneration air by condensing the compressedrefrigerant; a refrigerant evaporator for cooling the process air byevaporating the refrigerant condensed with the refrigerant condenser;and a desiccant wheel, having a desiccant which is regenerated by theregeneration air heated with the refrigerant condenser as theregeneration air passes through the desiccant and which processes theprocess air as the process air passes through the desiccant; wherein theprocess air blower, the regeneration air blower, and the compressor arepositioned vertically below the desiccant wheel, and the refrigerantcondenser is positioned vertically above the desiccant wheel.
 40. Adehumidifier as recited in claim 39, wherein the process air is cooledwith the refrigerant evaporator after being processed with thedesiccant, and the refrigerant evaporator is positioned vertically abovethe desiccant wheel.